Moabites, descendents of Moab, were peaceful people remaining near their ancestral home in the proximity of Zoar, displacing the Emmi (Deuteronomy 2:10, 11). The territory of the Moabites, at its largest extent, included three sections: the “field of Moab” (Ruth 1:1, 2), a tract enclosed by natural fortifications, on the north by the chasm of the Arnon, on the west by cliffs rising almost perpendicularly from the shore of the Dead Sea, and on the south and east by a semicircle of hills which open only for the Arnon and another Dead Sea torrent; the “land of Moab,” the more open country extending from the Arnon north to the hills of Gilead; and the so-called “plains of Moab” (Numbers 22:1), described as “the sunk” district in the tropical depths of the Jordan valley. Before the arrival of Israel, Shihon, the Amorite king, had taken most of this land from the former Moabite king so the penned up “field of Moab” was all that remained.
Coming up from Egypt the Israelites approached Moab through the desert “facing Moab,” outside of the bordering circle of hills on the southeast. They were forbidden from molesting the Moabites in the enjoyment of the land which they had taken from the Emim. Scriptural confusion occurs because it appears that when the Israelites requested permission to cross both Moab and Edom territory their request was denied (Deuteronomy 23:4), while scripture Deuteronomy 2:29 seems to indicate that both countries granted the Israelites right of passage. However the confusion is resolved when it is understood that the Israelites were to passed through Edom on the royal highway (Numbers 20:17), but the martial Edomites objected to this; and the Moabites appeared to take a similar course of action. Therefore, the Israelites passed along the boarder of both countries. In Judges 11:25, 26 it is specially noted that Moab did not fight the Israelites while they were neighbors for three hundred years.
The peaceful nature and rich possessions of the Moabites may be, in fact, the very reason why Balak was terrified at the approach of the Israelites, and may account for the special means he took to guard against them. Instead of taking up arm like Sihon, Balak called together the elders of Midian, Moab and Midian were related because of their common descendant from Terah (Genesis 11:27; 19:37; 25:2). As a result of this meeting the two nations agreed to send for Balaam, a diviner. Balak in desperation want to make a human sacrifice similar to that made by a later king of Moab, but he was retrained from doing so by Balaam.
Although relations between the Moabites and Israelites remained peaceful there were causes for tension. One of the principle causes of their friction was the hiring of Balaam by Midian and Moab, the Israelites were forbidden to believe in diviners and the cults of the other two nations. Another cause was the friendly relationships that the amorous young Moabite women struck up with the Israelites, which led the Israelite men to idolatrous practices and war between the two peoples. These events occurred during the time when the nations were engaged in trade; even then, Midian is mostly mentioned in connection with trade while the Moabites were mostly mentioned in the connection of marriage (Numbers 25:1).
Afterwards the nations engaged in sporadic fighting. Saul fought against Moab, although early relations between Moab and Israel appeared to be friendly. As described in the Book of Ruth, Ruth brought a Moabite element into the line of David. And David, when pressed by Saul, entrusted his parents into the keeping of the king of Moab. However, twenty years later for some unknown reason David became angry with the Moabites (2 Samuel 8:2) and their spoil, along with those of other nations, went to swell the treasury to build the temple. The Moabites became tributary. They are again mentioned in Solomon’s time sending their daughters to divert him. A.G.H.
Unger, Merrill F., Unger’s Bible Dictionary, Chicago, Moody Press, 1966, pp. 753-755