Jerusalem isn't mentioned in Islam's "Koran," but I don’t think it's mentioned in the Five Books of Moses either. I've heard it argued that the Koran's omission of Jerusalem shows a lack of connection between Islam and Jerusalem, but can't the same be said of Judaism?
Jerusalem is mentioned many hundreds of times in the Jewish Bible. As for the Chumash (Five Books of Moses), it is true that the exact word "Jerusalem" does not appear there. Most simply, this is because it was not yet called Jerusalem, and it had not yet been revealed as G-d’s chosen city.
Under Jebusite rule and earlier, Jerusalemwas divided into two cities, the western part called Jeru (Yere) and the eastern part called Salem(Shalem). Both of these names do appear in the Five Books: "And Malki-Tzedek, King of Shalem" (Genesis 14:18). "And Abraham called that place...Yere" (Genesis 21:14).
Around the time of Joshua's conquest, the Amorites consolidated the two halves of the city, and they combined the two names: Jeru-salem. From this point on in history, our Bible refers to Jerusalem countless times.
Furthermore, the Chumash refers 19 times to "the place that G-d will choose" as the center for Jewish life and religion (e.g. Deuteronomy 12:11, 14, etc.). The Prophets Samuel and Gad finally reveal to King David that this chosen place is Jerusalem and the Temple Mount.
So these are two reasons Jerusalem isn't mentioned explicitly in the Chumash as the holy city: It hadn’t yet been called that; and it hadn't yet been revealed as such.
Maimonides, writing around 800 years ago, offers three reasons that the Chumash does not explicitly reveal the identity of the holy city:
1. If the nations had learned that this place would express the highest Jewish ideals, they would have united in an effort to occupy and prevent the Jews from ever controlling it. (Sound familiar?)
2. If they had known of Jerusalem's special spiritual stature, they may have tried to take advantage of its spiritual nature by making it into a center of idol worship.
3. Each of the twelve tribes would have desired to have Jerusalem in their borders, and this would lead to disunity.
Once the Jews had conquered and divided the land, the above ceased to be considerations.
So, in conclusion, Jerusalem played a prominent part in Jewish history and writings more than two thousand years before Islam's rise and the writing of the Koran, which makes no mention of Jerusalem, despite the fact that by then it had certainly become known as the holy city of the Jews.
- Sources: Jerusalem, Eye of the Universe, by Rabbi Aryeh Kaplan