Exodus 34:12-15

Take care, lest you make a covenant with the inhabitants of the land to which you go, lest it become a snare in your midst. You shall tear down their altars and break their pillars and cut down their Asherim (for you shall worship no other god, for the LORD, whose name is Jealous, is a jealous God), lest you make a covenant with the inhabitants of the land, and when they whore after their gods and sacrifice to their gods and you are invited, you eat of his sacrifice