Numbers 25:1-5

1And Israel abode in Shittim; and the people began to commit fornication with the daughters of Moab.

2And they invited the people to the sacrifices of their 1gods; and the people ate, and bowed down to their 2gods.

3And Israel joined himself to Baal-Peor; and the anger of Jehovah was kindled against Israel.

4And Jehovah said to Moses, Take all the heads of the people, and hang them up to Jehovah before the sun, that the fierce anger of Jehovah may be turned away from Israel.

5And Moses said to the judges of Israel, Slay every one his men that have joined themselves to Baal-Peor.