Aijalon (ăˈjəlŏn, Īˈ–, āˈ–) [key], in the Bible. 1 Town, on the border between Philistia and Israel, the modern Yalo (Israel), NW of Jerusalem. In the Tell el Amarna letters it is called Aialuna. 2 Town in Zabulon. 3 Valley over which Joshua commanded the moon to stand still.