מדרש על ויקרא 20:23

5) (Vayikra 20:23) "And you shall not walk in the statutes of the nation" — the Egyptians. "which I am sending away before you" — the Canaanites. "For all of these they did": We are hereby apprised that the Canaanites were steeped in these things, and I am exiling them only because of these things, as a man who despises his food.