However, by the time of Israel’s Exodus, they had invaded Moabite and Ammonite territory E of the Jordan, taking possession of the region from the torrent valley of Arnon in the S (thereafter the border of Moab), up to the torrent valley of Jabbok in the N (the border of Ammon). (Nu 21:13, 24, 26; Jos 12:2; Jg 11:22) This was the realm of Amorite King Sihon, described by Josephus the Jewish historian as “a region situated between three rivers [the Jordan, the Arnon, and the Jabbok], which give it something of the nature of an island.” (Jewish Antiquities, IV, 95 [v, 2])

Conquest by Israel. Drawing near the Promised Land and under divine orders not to trespass on the territories of Moab and Ammon (De 2:9, 37), the Israelites requested a transit permit from King Sihon at his capital city, Heshbon, offering stringent guarantees: “Let me pass through your land. We shall not turn off into a field or a vineyard. We shall drink water of no well. On the king’s road we shall march until we pass through your territory.” Instead, Sihon struck at Israel with his combined forces and was summarily defeated a short distance from Heshbon, at Jahaz, his entire territory falling into Israelite possession. (Nu 21:21-32; De 2:24-36; see SIHON.)