Numbers 25:3

25:3 When Israel joined themselves to Baal-peor, the anger of the Lord flared up against Israel.

Numbers 8:19

8:19 I have given the Levites as a gift to Aaron and his sons from among the Israelites, to do the work for the Israelites in the tent of meeting, and to make atonement for the Israelites, so there will be no plague among the Israelites when the Israelites come near the sanctuary.”