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."
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.