Speaking Russian in Israel

Living in a neighborhood with many Russian immigrants and bilingual Russian/Hebrew signs everywhere, I decided it was worth my while to try and learn some Russian this last year. By now I know the alphabet, can read words reasonably well, and know the meaning of a few common words.

It seems to me that Russian speakers learning Hebrew, and vice versa, have a special advantage because those languages share more interesting characteristics than would be expected given their disparate origins. For example:

-The letter for "sh" looks exactly like a Hebrew "shin".
-The alphabet is derived from Greek, making it much more similar to Hebrew than the alphabets used in Western countries.
-The letter "B" by itself is a prefix meaning "in", just like in Hebrew.

In addition, there are many words in modern Hebrew, for example "protektziya" and the name "Netanya", that have a -ya ending. It seems to me that in pre-modern Hebrew this ending was much less common (except when referring to God's name, for example at the end of people's names). But it is very common ending in Russian.

I suspect that when the first Zionists came here from the Russian Empire, starting kibbutzim and formulating the modern Hebrew language, the new words they invented used the "-ya" ending because that was what they were familiar with. Indeed I wonder how many words like "protektziya" sound roughly like the English equivalent, but sound exactly like the Russian equivalent. I have no way of knowing, but suspect it's more than a few.

Early Reform Jews declared that the German language was the best language in which to express spiritual and moral ideas. Whatever the truth of that claim, it does seem that Russian was the most convenient language from which to begin the project of secular Zionism.

Shabbat and the Temple

From Birkat Hamazon:

רחם נא ה' אלוהינו, על ישראל עמך, ועל ירושלים עירך, ועל ציון משכן כבודך, ועל מלכות בית דוד משיחך, ועל הבית הגדול והקדוש, שנקרא שמך עליו.
"Please have mercy Hashem our God, on Israel Your people, on Jerusalem Your city, on Zion the dwelling place of Your honor, on the kingdom of the dynasty of David Your servant, and on the great and holy Temple which your name is attached to."

On Shabbat:
רצה והחליצנו ה' אלקינו במצוותיך ובמצות יום השביעי השבת הגדול והקדוש הזה.
"May you strengthen us Hashem our God in your mitzvot, and in the mitzvah of the seventh day, this great and holy Sabbath."

[I make no pretense that these are great translations. My blogging philosophy right now is "quantity not quality".]

It is interesting that the same phrase, "great and holy", is used to describe both Shabbat and the Temple in the same blessing. Indeed, there is a precedent in the Torah for linking Shabbat to the Temple:
את שבתתי תשמרו, ומקדשי תיראו, אני ה'.
"You shall guard my Sabbaths, and revere my Temple - I am Hashem." (Vayikra 19:30)

In other contexts we see additional connections between Shabbat and the Temple. For example, the words "kidush" and "hilul", sanctification and desecration, are obviously applicable to the Temple, and are used many times when the Torah discusses the Temple. But they also appear in the context of Shabbat. The performance of work on Shabbat is called "hilul Shabbat", rather than something like "aveirah al mitzvat shabbat". And there is a positive mitzvah to be "mekadesh" Shabbat, not just to remember it. This Temple-like language in relation to Shabbat (and holidays) is second nature to us, but the basic observance of Shabbat could easily be described without it, so we must ask ourselves why it is there.

What is the meaning of the linkage between Shabbat and the Temple? To understand it, we can rely on R' Soloveitchik's explanation of how Shabbat and holidays are similar yet different (in Shiurim Lezecher Abba Mori, Kivud veOneg Shabbat).

Basically, on Shabbat God visits us (לכה דודי לקראת כלה), while on holidays we visit God, at the Temple (שלוש פעמים בשנה יראה כל זכורך את פני ה' אלקיך במקום אשר יבחר). Both Shabbat and Temple visits are encounters with God; the only difference is who is traveling to encounter whom.

Thus they are mentioned together in Vayikra 19:30, and are described the same way in birkat hamazon.

Thoughts on Vayelech

[Moshe] said to them: "I am a hundred and twenty years old this day; I can no longer go out and come in; and Hashem has said to me: 'You will not pass over this Jordan.' Hashem your God, He will pass over before you, He will destroy these nations from before thee, and you shall dispossess them; and Yehoshua, he will pass over before you, as Hashem has said." (31:2-3)

What does it mean to "go out and come in"? Moshe has just been giving long speeches to the entire people, so it cannot mean that at age 120 he is incapacitated and bedridden!

In fact, we see from many other places in Tanach that "to go out and come in" has a specific meaning: to go out to battle, and to come in from battle. With this understanding, the continuation of our passage follows logically: Moshe cannot go to battle, so Yehoshua and figuratively God will have to lead the conquest of Canaan.

From where do we know that "to go out and come in" generally refers to battle? Here are some sources. The first one is the most explicit.

Kalev ben Yefuneh arguing why he should be the one to conquer and inherit Hevron:
"As my strength was then, so is my strength now, for war, and to go out and to come in." (Yehoshua 14:11)

David fighting the Philistines:
"The Philistine princes went out, and it happened that whenever they went out, David did better than all of Shaul's servants." (Shmuel Alef 18:30)

Shaul stops sending his army to capture/kill David, because he does not know where David has fled to:
"Then David and his roughly 600 men rose and left Keilah, and went wherever they could go. It was told to Shaul that David had fled Keilah, and he stopped going out [after David]." (Shmuel Alef 23:13)

Achish king of Gat explains to David why he must leave the Philistine camp as they go to fight Israel, because the other Philistines think David will betray the Philistine side. Background: David has lived with Achish and launched periodic raids against Amalek, but told Achish that the raids were actually against Israel.
"You have been upright, and your going out and coming in with me in the army is good in my sight; for I have not found evil in you, from the day of your coming to me unto this day. Nevertheless, the [other] lords do not like you. Now go, depart in peace." (Shmuel Alef 29:6-7)

When Shlomo first became king he was not confident in his ability to conduct royal affairs, unlike David his father.
"And now Hashem my God, you have made your servant king in place of David my father, but I am a young lad, I do not know about going out and coming in." (Melachim Alef 3:7)

And last, a well-known verse. This *could* be another example, but it also makes perfect sense even if the subject is not limited to war.
"May Hashem guard your going out and coming in, from now and forever." (Tehilim 121:8)

It's raining!

And it's not even Rosh Hashana yet.

Either we added one too many leap months, or for the first time in however long we are going to have a non-drought year.

Hopefully the latter.

Thoughts on Ki Tavo and Nitzavim

It's been a while since I've done a "Thoughts on ____" post. Or rather - since I've finished such a post. I have started but not finished several such posts in the meantime.

Sefer Devarim has the following structure, with the numbers referring to chapters:

1-4 - Initial speech
5-26 - Really long speech with a zillion mitzvot in it
27 - Instructions for ceremony on Mt. Eval
28 - Blessings and curses
29 - "Nitzavim" speech
30 - Teshuva etc.
31-34 "The last day" - stuff Moshe has to do before he dies

(Parshat Nitzavim consists of chapters 29 and 30, minus the beginning of chapter 29.)

I separated chapters 27, 28, 29 and 30 the way I did because chapters 27 and 29 address Israel in the plural, while 28 and 30 address Israel in the singular. Chapter 28 is the text of a covenant, to which chapter 30 is apparently an appendix. In contrast, chapters 27 and 29 are speeches given by Moshe. [I wrote about this structure for DBH way back in 2003, for some reason it does not appear in the archives.]

What should bother you about this structure is that chapters 28 and 29 have very similar content. First we have a covenant in which we are promised blessings if we obey and curses if we disobey. Immediately after this in chapter 29, we have a speech saying the exact same thing: if you disobey, you will suffer! Why the repetition?

The answer is that Chapter 28, like most promises of reward and punishment in Tanach, talks about the behavior of the entire people. If we all obey, we will collectively be rewarded, and similarly if we disobey. The chapter begins by saying: "And it will be, if you obey Hashem your God, to carefully perform all his commandments which I command you today - then Hashem your God will make you ascendant over all the peoples of the earth." An individual cannot "become ascendant" relative to a nation - only another nation can. Evidently this line - and it seems all the blessings and curses which follow it - are talking about collective reward and punishment, naturally for collective good and bad behavior.

In contrast, chapter 29 talks about the behavior of individuals: "Lest there is among you a man or woman or family or tribe, whose heart turns away today from Hashem our God" (29:17). What do these individuals do? "...And when he hears the words of this curse, he will bless himself in his heart to say 'I will have peace when I follow the arbitrariness of my heart' " (29:18). Evidently, he assumes that the curses talk about communal behavior. But he is simply an individual sinner, insignificant compared to the rest of the community. So he thinks the curses do not apply to him personally, and he can get away with his misbehavior.

Right after that, Moshe corrects this misimpression, by describing how the deviant individuals or tribe will indeed be punished.

However, Moshe then describes the results of this punishment: exile, and the destruction of the land the exiles used to live on. We are still in the speech of chapter 29, but suddenly this looks much more like a collective than an individual punishment!

I can think of two explanations for this change, one of which is my own, one which appeared in a recent issue of "Daf Kesher" (which I can't find now).

The first explanation is that we have simply gone from talking about individual people to individual tribes, and a whole tribe can be (and was on occasion) punished and exiled while the rest of the people remains unpunished.

The second explanation is that an individual sinner, if left unpunished, will influence others to do the same until the entire people is involved - שורש פורה ראש ולענה. As a result, we are obligated to punish individual sinners to prevent the misdeeds from spreading. Thus the last line of chapter 29 states that "The secrets belong to Hashem our God; but the revealed things belong to us and our children forever, that we may do all the words of this Torah." If a person sins in secret, there is nothing the rest of us can do about it. But if their sins become revealed, then our duty to punish them, and to prevent more sins in the future, comes into play.

Yaakov and divorce

When Yaakov was tricked into marrying Leah, whom he never wanted to marry, why didn't he then divorce her? Moreover, how did Lavan know ahead of time that he wouldn't divorce her (because if not, his trickery would have been futile and not worth doing)?

One might be tempted to conclude from this that divorce was impossible, or at least extremely frowned upon, before the giving of the Torah. The Mishna discusses (Gittin 9:10) whether divorce can be "no-fault" or should only come as a result of adultery. If the latter was the case, at least before the giving of the Torah, then Yaakov might have been stuck with Leah, lest he severely dishonor both of them by implying that adultery had taken place. And if divorce was nonexistent, then Yaakov would have been even more stuck.

There is however a verse which might indicate otherwise, that divorce was acceptable at the time.

"Esav saw that the daughters of Canaan were displeasing to Yitzchak his father, so Esav went to Yishmael, and married Machalat daughter of Yishmael Avraham's son, the sister of Nevayot, in addition to his [existing] wives." (28:8-9)

What is the point of saying "in addition to his wives"? We already know he has wives (they were the motivation for Yitzchak's displeasure), so what does this phrase add to the verse?

It could just be redundant, since we know that genealogies and similar passages in the Torah do often include redundancy, and this passage is in a relatively similar style.

But it is also possible that the phrase is teaching something new: that Esav could and should have divorced his Canaanite wives, but chose not to. Thematically, this seems likely: the influence of Canaanite idolatry in the household would not be removed by marrying a righteous wife, but by removing the evil ones. At the same time, divorcing a wife whom you still love is no easy task. Esav recognized the problem but was not willing to sacrifice in order to solve it. Rather, he took the easy way out and applied a band-aid solution, marrying a new wife instead of divorcing the old ones.

If the latter approach is correct, we must ask why Yaakov too did not divorce his wife when he had the option. It seems to me that the fact Yaakov chose this way, and Lavan knew he would chose that way, indicates something positive about Yaakov's character.

In the ancient Near East, divorced women would have been at a large disadvantage on the marriage market - they were no longer virgins, and may have suffered the previously mentioned suspicion of past adultery. And Leah was unattractive to start out with. Why would Lavan arrange a trick marriage for Leah unless he despaired of finding a regular marriage? In addition, in a society where men did the farming and trading, a woman of any status had little purely economic value. If Yaakov divorced her, Leah would likely live the rest of her live single, lonely, and resented as a financial burden on her family. It is to Yaakov's credit that he spared her this fate, remaining married to her when he had no desire to marry her in the first place.

Indeed, Yaakov's considerations seem to be the original moral justification for allowing polygamy (a justification which, clearly, would not exist in modern society). But while polygamy permitted a man to marry a second wife whom he desired, in a way that was beneficial to both of them, Yaakov's decision was not mutually beneficial. It did nothing for himself, but a great deal for Leah.

Lavan knew ahead of time that Yaakov would probably act this way. He surely felt that he was getting the best of the deal, by taking advantage of Yaakov's foolish piety. But in the historical record, it is he who comes off as beneath contempt, while Yaakov more than succeeds in retaining his moral dignity.

Most amazing invention

The most amazing invention of the 20th century is undoubtedly GPS.

Think about the technology needed to make it work:
- Space flight - putting satellites in orbit around the earth
- Computer - a tiny piece of silicon, relying on quantum mechanics to work, that can do a billion calculations a second.
- Wireless communications - by which pieces of electronics thousands of miles apart can invisibly send information between them
- The theory of relativity - without it the GPS calculations would be way off

And all of this to solve a problem which has affected people for thousands of years, inspiring the development of the compass, astrolabe, much of astronomy, and the development of precise clocks.

If the price of GPS receivers ever drops much lower, and they become much smaller (and both are likely to occur), we will see GPS used in all sorts of devices. For example, your keychain. If you ever lose your keys, you'll be able to go to your computer, type in "where are my keys". It will send a wireless internet signal to the keys, the keys will respond with their GPS data, and the computer will tell you "on the floor of the upstairs bedroom, along the north wall, 2 feet from the window". How cool will that be?

livesContentsk

Ever see the word "livesContentsk" before?

Apparently Microsoft Word, or some version of it, is stupid enough to think that every occurrence of the letter sequence "toc" must refer to a table of contents.

The structure of selichot

At the beginning of selichot is a section entitled "Shomea tefilah" which consists of 47 mostly Biblical verses, one after the other in a very long paragraph.

To understand what is going on in this paragraph, we must note what the verses have in common with one another. Thematically, all the verses seem more or less appropriate for a prayer service such as selichot. But there is significant variation between them, and one would be hard pressed to find any consistent pattern based on their content alone.

There is, however, a clear pattern by which we can organize the paragraph; it is linguistic rather than thematic. Each of the first seven verses in the paragraph contains a variation of the verb "lavo", "to come". In five out of seven verses, the verb "lavo" is the first word in the verse. In all seven verses, that verb is arguably the most important word. In this section, "lavo" is a "guiding word" (מילה מנחה), which appears multiple times and is intended to emphasize the linkage between the verses.

This kind of pattern is not limited to the first seven verses. In fact, if you examine the entire paragraph, you will find that every verse includes an important "guiding word" which is shared with the verse before or after. The whole paragraph is a series of units, each of which is defined by its guiding word. That is the basic structure, which unifies the disparate themes which appear throughout the paragraph.

Here is a list of the guiding words found in each verse, along with a count of consecutive verses that include that word.

Yavo'u, yavo, yavo'u, bo'u, navo'ah, bo'u, navo (7)
Barchu, barchu (2)
Romemu, romemu (2)
Vehishtachavu, vehishtachavu, hishtachavu, nishtachaveh (4)
Mi, mi (2)
Gadol, gadol, gadol, gadol, gadol (5)
Mi, mi (2)
Me'ein kamocha, me'ein kamocha (2)
Lecha, lecha, lo (3)
Gevurot, gevurah (2)
Lecha, lecha (2)
Atah, atah, atah, atah, atah (5)
Kodsho, kedoshim, kedoshim (3)
Nekadma, yekadmu (2)
Asher, asher, asher (3)
Haneshama, haneshama (2)
Shimcha, shimcha, shimcha (3)

[Note: Add together the numbers in parenthesis and you will get 51 not 47 verses. This is because 4 verses include two guiding words each, one from the set before, one from the set after.]

In order to understand the larger structure of the paragraph, we can translate the guiding words and list them in order. Then, looking back at the original text to verify that the context is correct, it seems we can divide them into the following three categories:

- Come, bless, exalt, bow
- Who, great, who, unique, yours, greatness, yours, you
- Holy, come, about, soul, name

The first group is an initiation of prayer, the second group discusses God's power and special attributes, the third group discusses God's holy status and "name" as a result of worship by angels and humans. Quite obviously, these three groups parallel the first three brachot of Shemoneh Esreh.

As has been pointed out elsewhere (I heard it from R' Moshe Aberman), the entire structure of selichot - ashrei, kaddish, the stuff in the middle, tachanun, kaddish - is very similar to the structure of a prayer service. We see now that the parallels go much further, since the "stuff in the middle" of selichot parallels Shemoneh Esreh. As discussed above, the long "Shomea tefilah" paragraph at the beginning closely resembles the first three brachot. The repeated sets of 13 attributes in the middle of selichot, each preceded by a complex poetic paragraph, parallel the intermediate brachot of Shemoneh Esreh. The end of slichot, before the tachanun part, consists of a "shma koleinu" paragraph, as well as a "zachor" paragraph requesting the rebuilding of the Temple like in the "retzeh" blessing (granted, "zachor" precedes "shma koleinu" in selichot, while in Shemoneh Esreh the opposite is true).

There is no clear parallel in selichot to the Modim and Sim Shalom blessings. But except for that, the structures of selichot and Shemoneh Esreh are virtually identical.

Moral hazard

Watching the business news over the last couple weeks has given me a feeling I have rarely felt before in my life. The news is bad, but more than that, it is so vast and unimaginable that it is hard to comprehend its impact. It's like missing the newspapers for a couple days, and the next time you sit down to read them, you find out that the Germans have occupied France.

It is hard to comprehend that the entire profession that many people I know went into, may soon cease to exist.

The main argument against the government protecting banks like AIG from failure is the existence of "moral hazard", that investors will know that the government will save them in the event of a crisis, so they will not have to bear the full extent of their risks. With this implicit guarantee, they will be willing to make unjustifiably risky investments which they shouldn't make. I am not an economist, but I'm not sure the "moral hazard" argument is applicable to the current crisis.

The people buying complex derivatives, who would be on the hook for most of the losses, did not understand what they were buying. For that matter, the people who made them in the first place didn't always understand them! And home-buyers who took out unreasonable mortgages certainly had no way of knowing that the lenders were irresponsible.

People did not make bad decisions assuming that the government would bail them out. People made bad decisions because they mistakenly thought a bailout situation would never arise.

The "moral hazard" theory presumes that people will rationally decided that investments which are bad for society are nevertheless worthwhile for themselves. In the current crisis, we had no such rational thinking, only irrational thinking based on misunderstandings. Moral hazard did not create this crisis, and will not create a future crisis of the same nature (though it could contribute somewhat to a preexisting crisis, including this one).

I know of at least one financial services person who reads this blog, any comments?

If only they knew

In the news today: "Many Arabs envy Israel because of our ability to topple serving prime minister."

Ha! Almost since the day Olmert took office 2+ years ago, the vast majority of Israelis have wanted to topple him. If only we were able to!

The file

On my computer I have a file full of unfinished blog posts. Right now, includes 91 posts-in-progress totaling 24,000 words. Some of the in-progress posts have not been touched in a year or two; some were begun as recently as last week.

Where is my motivation to finish these posts?

David's flight from Shaul

David's flight from Shaul, according to Sefer Shmuel (Alef chapter 19 - Bet chapter 2). David starts in Beit Lechem (his family home), and finishes in Hevron, after Shaul has died and he has become king.

Some speculative place identifications are based on shiurim from R' Yaakov Medan. Original map is from Koren Tanach.

Here is what David did in each place:

Ramah, Nayot be-Ramah - chased by Shaul
Givah - meets Yonatan, who shoots arrows as a signal
Nov - hides, city later massacred by Shaul
Gat - pretends to be insane, leaves
Adulam cave - hides, collects fellow rebels
Mitzpeh Moav - stays under Moav's protection
Forest of Heret - returns from Moav
Keilah - defeats Philistines, then chased away by Shaul
Zif, Maon - chased by Shaul
Ein Gedi - hides with his men
Midbar Paran - hides with his men. Sends messengers to Naval who refuses to help. Marries Avigail when Naval dies.
Givat Hahachila - penetrates Shaul's camp at night
Gat - stays with Philistines, fights Amalekites, is given Tziklag by Philistines
Afek - joins Philistine camp going to fight Israel in Yizrael, but they doubt his loyalty and send him home
Tziklag - city sacked by Amalekites, David avenges it
Hevron - Philistines have killed Shaul so David returns to Israel and becomes king

Nefesh Benefesh

Nefesh Benefesh does a number of great things to help new olim from the US and other English speaking countries.

There is just one thing they've done wrong, and it was the very first thing they did - choosing their organization's name.

You see, when the phrase "nefesh benefesh" is used in the Torah, it refers to the death penalty for bearing false witness in a murder case!

I wonder if they chose the name knowing this, or if it just got by their name screening committee and since then nobody has had the heart to point it out.

Truth from Shalom Carmy

(Tradition 33:2 p.32)

The H-Bomb

It's said that Harvard students are reluctant to name their college in conversation, instead resorting to euphemisms such as "a college in the Northeast" or "in Boston". Why? Because of the extraordinary mixture of awe and envy that most people feel towards that school in Cambridge. Once the student mentions "Harvard", the inevitable response is a knowing "Oh, Harvard..." and the student is no longer simply a student, but the object of every preconception and attitude the other person possesses regarding that one university. All the stereotypes of intelligence and achievement, of arrogance and sense of entitlement, immediately come to the fore, and it's difficult to continue the conversation on the same footing with which it began. This phenomenon is known colloquially as dropping the H-Bomb, and to avoid it Harvard students often obscure the details of where they really go.

I feel that a similar situation exists regarding my academic program - a master's degree in electrical engineering in Haifa's engineering university. Before even arriving I had to deal with people calling me a "gaon" just for getting in here, and once here, EE has a well deserved reputation as the hardest subject in the university. But once I've named my university and subject, things get even worse. I am inevitably asked how far along in my bachelor's degree I am, to which I must reply that I'm in the master program. At this point, I get something very nearly approximating the "Oh, Harvard" response.

You see, there are about 2000 undergrads and 300 grad students in the EE department here. That basically means that only the top 15% of undergrads qualify for graduate study. Entering the Technion is an achievement, surviving the undergrad EE curriculum is an achievement, and qualifying for the masters program is the biggest achievement of all. So in everyone's mind, I form part of the elite of the elite of the elite. Once mentioned, my status can make people relate perceptibly different to me, at least temporarily.

Of course, this status is misleading. Unlike nearly all grad students here, my undergrad degree was obtained in the US. The EE program at my American university was much inferior to the undergrad program here. The admission standards here are apparently significantly lower for foreign students, because our presence helps the university to market itself as part of the international academic community. When I came I had an incredible amount of catchup to do, and two years later my total research accomplishments are little to be proud of.

When I explain this, people do understand. All I have to say is, "It's not like that. I got my bachelors degree abroad. It was a lot easier for me than for my peers here." And just like that, I revert to being a normal human being.

Torah and Medicine

I always find it weird how obsessed Modern Orthodox Jews are with medical ethics topics. I mean, why do so many people care about the exact halachic definition of death, who don't care about the exact halachic definition of intent while performing a mitzvah? Why is the halachic discussion about terminating pregnancy more interesting than the halachic discussion about terminating a business partnership? Why are these shiurim and others like them so heavily advertised, while I have yet to hear about a lecture series entitled "Topics in Sefeikot" or a shiur on "Shitat haRambam on Edut Shebichtav"?

The obvious explanation is that so many MO Jews are going to be doctors, and not only for financial reasons, but also due to a bit of idealism that medicine is a religiously valuable profession. So they naturally prefer topics which they know about, and which make their practice a little bit more religiously valuable. All of which is perfectly logical.

But still, for us outsiders, it's weird. Personally, I'm waiting for a shiur on lossy dielectrics. Failing that, I will settle for a discussion of the hashkafic implications of cascode differential amplifiers. If I were to give a chaburah on either of those topics, which of you wouldn't come?

Trivia question

Q: Which Israeli community has numbered, parallel streets going all the way up to 67th street?

A: Kiryat Chaim, a suburb of Haifa. Many of the streets have apparently received "real" names over the years, but many others are still called by their numbers, written out in the Hebrew-letter numbering system.

Heard in pre-maariv shiur tonight

In 1967 the Israeli government predicted that they would win the war, but at the cost of around 60,000 deaths. There were not enough spots in all of Israel's cemeteries for 60,000 corpses, so they took all the public parks and prepared to use them as cemeteries. There wasn't anyone to dig the graves, though, because all the men were in the army. So they took all the yeshiva students in the country and prepared to have them dig graves. God did not want those yeshiva students to have their Torah study interrupted, so He made sure the war would end quickly with a minimum of Israeli casualties.

Um... right. And I thought I liked that synagogue.

The four-entrance tent

You know the midrash about how Avraham Avinu had openings on all four sides of his tent, so as to be able to more easily greet visitors coming from any direction? I wonder if that wasn't the only reason there were four openings. This suspicion is based on what I'm experiencing right now.

I have windows on both the east and west sides of my apartment. Normally a strong wind blows through one window and out the other, making it pleasant in the apartment despite the August heat and no air conditioning.

Today, however, there is no breeze and I'm sweating away just sitting in front of the computer. Annoyed at the situation, I happened to go into my bedroom, which has an open window facing north. There I encountered an extremely strong breeze! Clearly it would be best if the apartment had windows facing in all four directions. Then I would benefit from the east-west breezes, when those existed, and from the north-south breezes the rest of the time.

We know that Avraham was "yoshev petach haohel kechom hayom" - in the hot part of the day. That is exactly the time he would most have appreciated a breeze from whatever direction it might come. And so it makes perfect sense that he would have had openings on all four sides of the tent, if only for that reason, not just for reasons of hospitality.