Numbers 25:17

“Vex the Midianites, and smite them.] Go to war with them, and smite them with the sword; not the Moabites, but the Midianites, though they were both confederates against Israel; but God had given a charge not to contend in battle with Moab, (<050209>Deuteronomy 2:9), they were spared for the sake of Lot, from whom they sprang; and, as Jarchi says, for the sake of Ruth, who was to come from them; and so in the Talmud f415; though they did not entirely escape the divine resentment, as appears from (<052303>Deuteronomy 23:3,4) but the Midianites were the first that advised to send for Balaam, and with them he stayed and was entertained, after he had been dismissed by Balak; and it seems as if…”

“Vex the Midianites, and smite them--They seem to have been the most guilty parties. (Compare Num 22:4; Num 31:8).”

“The Midianites - And why not the Moabites. It is probable the Midianites were most guilty, as in persuading Balak to send for Balaam, Num 22:4, Num 22:7. So in the reception of Balaam after Balak had dismissed him, Num 31:8, and in farther consultation with him, and in contriving the means for the executing of this wicked plot. Numbers 25:18”

“Balaam's counsel seems to have been first given to Balak, king of Moab; but probably the Midianitish women, especially of the higher ranks, as Cozbi was, were the principal tempters; and the nation of Midian seems to have come into the execrable measure more generally and heartily than that of Moab. they were therefore first selected to be made examples of, for a warning to the Moabites, who were spared at this time. Num 31:2; Rev 18:6 Numbers 25:18”