Leviticus 18:26-28

So then keep my rules and my decisions, and do not do any of these disgusting things, those of you who are Israelites by birth, or any others who are living with you: (For all these disgusting things were done by the men of this country who were there before you, and the land has been made unclean by them;) So that the land may not put you out from it, when you make it unclean, as it put out the nations which were there before you.