Revelation 2:14 NKJV
But I have a few things against you, because you have there those who hold the doctrine of Balaam, who taught Balak to put a stumbling block before the children of Israel, tgo eat things sacrificed to idols, and to commit sexual immorality.

Numbers 25:6 NKJV
And indeed, one of the children of Israel came and presented to his brethren a Midianite woman in the sight of Moses and in the sight of all the congregation of the children of Israel, who were weeping at the door of the tabernacle of meeting.