2 Samuel 5:7

The stronghold of Zion: the same is the city of David. Zion was the hill on the southwestern side of the city; but we learn from 2 Samuel 5:9 that the Jebusites had not occupied the whole of it, but a part only, which was their stronghold, round which there would be scattered dwellings, as the whole tribe dwelt there. The total area of the hill top was about sixty acres, and it was now quickly covered with houses, and called "the city of David," after its captor. The view of Dr. Birch and others, that the stronghold of Zion was Ophel, is rendered untenable by the fact that this southern tongue of Mount Moriah is completely commanded by other parts of the hill. According to Gesenius, Zion means "sunny;" others render it "the dry hill;" others, "lofty;" and Furst, "the castle." None of these derivations is of any real value, as the word is probably Hittite.