Vex the Midianites, etc. - See this order fulfilled, Numbers 31:1-20. Twelve thousand Israelites attacked the Midianites, destroyed all their cities, slew their five kings, every male, and every grown up woman, and took all their spoils.
Matthew Henry
Concise Bible Commentary
We read not that any Midianites died of the plague; God punished them with the sword of an enemy, not with the rod of a father. We must set ourselves against whatever is an occasion of sin to us, Mt 5:29,30. Whatever draws us to sin, should be a vexation to us, as a thorn in the flesh. And none will be more surely and severely punished than those who, after Satan's example, and with his subtlety, tempt others to sin.
SDA Bible Commentary (limited)
Volume 1-7
17. The Midianites. The Midianites had collaborated with the Moabites in the campaign of evil against Israel. As descendants of Abraham they should have manifested a different attitude toward God’s people. The Moabites did not completely escape due punishment, but, presumably because of the promise made to Lot (Deut. 2:9) or because their cup of sin was not yet full (see Gen. 15:16), they were passed over for the time being. Eventually, the Moabites were shut out even to the tenth generation from the congregation of Jehovah (Deut. 23:3, 4).