18 For they are a danger to you with their false ways, causing sin to come on you in the question of Peor, and because of Cozbi, their sister, the daughter of the chief of Midian, who was put to death at the time of the disease which came on you because of Peor.
Matthew Henry's Commentary on Numbers 25:18
Commentary on Numbers 25:16-18
(Read Numbers 25:16-18)
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, Matthew 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.