1. Bamidbar 34
In parshat Matot/Masei, Israel makes some of its final preparations for the entry to the land of Israel. Bamidbar 34:16-29 lists the princes who will represent each tribe in apportioning the land to be conquered. The list goes as follows:
The ordering of this list is unexpected. It does not follow either of the two normal ways by which the tribes are ordered – by the order of birth of Yaakov's sons, or the order of marching in the desert. Why did the Torah choose to order the tribes this way?
Looking at a rough map of tribal territories, the answer becomes clear. The order of tribes here is the same as the geographic order of tribal inheritance, from south to north.
Yehudah inherited everything south of Jerusalem.
Shimon's territory was considered to be part of Yehudah's territory (Yehoshua 19:9). As such it is mentioned after Yehudah, even though it was in the more southern part of Yehudah.
Binyamin's territory was just north of Jerusalem.
Dan's territory was roughly the Tel Aviv area.
Efraim and Menashe inherited the northern West Bank. (Efraim's territory was south of Menashe - this seems to be the only real deviation in the list from geographic order. Perhaps it can be explained by saying that Efraim and Menashe, being brothers, were listed together, and Menashe as the elder came first. This explanation gains credence because both are listed here as being a subset of Yosef, and only secondarily as independent tribes.)
Yissachar and Zevulun's territories bordered Menashe, in the southern Galil. The territories were roughly adjacent to one another - Zevulun to the west, Yissachar to the east. (On the map above they forgot to label Yissachar! It was surprisingly hard to find a suitable map online!)
Asher and Naftali were the northernmost tribes, Asher to the west, Naftali to the east.
2. Similar lists
The Torah records two other lists of the tribes dating to the 40th year in the desert. These too seem to be ordered by future territory from south to north.
One list is in parshat Vezot Habracha (Devarim 33:6-24). The setting (the conquest of Canaan is about to begin) and the many references to the land make it clear that that's a main theme in Moshe's blessings. The order of blessings is:
Reuven, Yehudah, Levi, Binyamin, Yosef, Zevulun, Yissachar, Gad, Dan, Naftali, Asher
This is the same order as Bamidbar 34, except for the following deviations.
1) Reuven, Gad, and Levi appear. Reuven and Gad are omitted from Bamidbar 34 because they already received land on the east bank, Levi because they would not receive land at all. Nevertheless, they all deserve to be blessed here. Reuven and Gad are included in roughly geographic order. So is Levi, if you take Jerusalem as their eventual inheritance.
2) Shimon disappears. Presumably their blessing is shared with Yehudah, the tribe they eventually assimilated into.
3) Yissachar switches with Zevulun, and Asher with Naftali. Yissachar was east of Zevulun, not north or south, and Naftali was east of Asher. So it is equally logical to have either one before the other. The fact that these particular tribes switch places, while other tribes stay in the same order, strengthens the thesis that the ordering is geographical, south-to-north.
4) Dan moves towards the end of the list. In the end, Dan was unable to conquer its land in the south and went to conquer land in the north. Bamidbar 34 reflects the planned southern inheritance; the order of Devarim 33 is presumably a prophetic reference to the eventual northern inheritance.
The final list is Devarim 27:11-13, which explains the ceremony that will take place in Shechem, with 6 tribes standing on one mountain and 6 on the other. These are:
Yehudah, Shimon, Levi, Binyamin, Yosef, Yisachar stand on Mt. Gerizim (towards the south), while
Reuven, Zevulun, Gad, Dan, Naftali, Asher stand on Mt. Eval (towards the north).
Here, except for Reuven and Gad, it once again appears that southern tribes are listed before northern tribes. The explanation of Reuven and Gad may be that Mt. Gerizim was somewhat to the southwest rather than due south, and Mt. Eval northeast rather than due north. So the "north" mountain is really "northeast", and the eastern tribes Reuven and Gad fit there just as well as in the south.
(Note: I have changed the order of the tribes on each mountain from the list in Devarim 27, to make the similarity to the other lists clearer. I think the ordering in Devarim 27 is for literary reasons: each list of 6 tribes splits into two lists of 3 tribes, and each list of 3 tribes has the tribe with the shortest name in the middle. Presumably it sounds nicest that way.)
3. An implication
One implication of this list is that the tribal locations were decided upon before the conquest took place. This helps us explain many different verses in the Torah. For example:
1) In Breishit 38 Yehudah apparently settles in Adulam (a city near Beit Shemesh, in the tribe of Yehudah's future territory.) Perhaps this was no coincidence, and Yehudah intended to colonize land which he expected would eventually belong to him. (Similarly, Shimon and Levi may have expected to receive Shechem, hence their zealotry there. But as punishment, they lost their right to inherit as independent tribes. If so then Yehudah, Shimon, and Levi – three of the four oldest sons – would have received the most central inheritances, later given to Yehudah, Efraim, and Menashe. Perhaps the oldest son Reuven also would have received a valuable inheritance, but he too was disinherited.)
2) Yaakov promised Yosef “Shechem echad al achecha” (Breishit 48:22). This refers to the double inheritance of Menashe and Efraim. But it may also allude to the city Shechem itself – which was in Yosef's future territory.
3) The names of some Israelites are also the names of cities in the tribal territory each individual would later live in. For example: Shechem, Hefer, and Tirtzah from the tribe of Menashe, and Hetzron from Yehudah. Perhaps, these Israelites' parents gave them the names with the expectation that the kid or his descendants would later control that city. (However, the fact that the best examples of this are from Menashe suggests a different explanation: that these individuals lived in the territory of Menashe rather than leaving Egypt with Moshe, a thesis discussed here.)
4) Moshe's viewing of the land from Mt. Nevo (Devarim 34:1-2) mentions the names of five tribal territories in their correct locations, even though the tribes had not inherited yet. Similarly, Breishit 14:14 mentions the city of Dan, which had a different name (Laish) until long after the inheritance – a seeming anachronism.
Each of these verses can be understood clearly through the idea that the tribal locations were known before the conquest.
If so, then the “casting of lots” used to apportion territory (see Yehoshua 14:2,15:1,etc., and Bamidbar 26:55) must have served either to define the exact boundaries between tribes (which had never been precisely specified), or else simply to give a Divine stamp of approval to the previously agreed-upon division.
4. Why south before north?
Why does the ordering of tribes go from south to north, and not in some other direction? An east-to-west ordering makes little sense, since the land of Israel is longest in the north-south direction. But why south to north, not north to south?
I think this is easy to explain. Nowadays we have north at the top of our maps, but in the ancient Middle East, east was at the top. (As a result, the country Yemen was on the right side of the map. This is reflected in its name, which comes from the Hebrew word "yamin", meaning "right". Similarly the word "kedem", meaning "forward", also means "east" in Tanach.) A Hebrew speaker, who read writing from right to left, would naturally read the map from right to left - that is to say, from south to north, the same order we see here.
The same logic explains why the "blessing" of Gerizim and Eval was on the southern mountain, Gerizim. (You might expect the opposite, since the south is drier and less fertile in Israel). A person's right hand is stronger and has higher status than their left hand. In this symbolic ceremony, the mountain on the right is privileged as well.