Numbers 25:15

25:15 The name of the Midianite woman who was killed was Cozbi daughter of Zur. He was a leader ¹  over the people of a clan of Midian. ² 

Numbers 31:8

31:8 They killed the kings of Midian in addition to those slain – Evi, Rekem, Zur, Hur, and Reba – five Midianite kings. ³  They also killed Balaam son of Beor with the sword. ⁴ 

[25:15]  ¹ tn Heb “head.”

[25:15]  ² sn The passage makes it clear that this individual was a leader, one who was supposed to be preventing this thing from happening. The judgment was swift and severe, because the crime was so great, and the danger of it spreading was certain. Paul refers to this horrible incident when he reminds Christians not to do similar things (1 Cor 10:6-8).

[31:8]  ³ sn Here again we see that there was no unified empire, but Midianite tribal groups.

[31:8]  ⁴ sn And what was Balaam doing among the Midianites? The implication is strong. This pagan diviner had to submit to the revealed will of God in the oracles, but he nonetheless could be hired. He had been a part of the attempt to destroy Israel that failed; he then apparently became part of the plan, if not the adviser, to destroy them with sexual immorality and pagan ritual.