Leviticus 11:43

11:43 Do not make yourselves detestable by any of the swarming things. You must not defile yourselves by them and become unclean by them,

Leviticus 18:24

Warning against the Abominations of the Nations

18:24 “‘Do not defile yourselves with any of these things, for the nations which I am about to drive out before you have been defiled with all these things.

Leviticus 18:28

18:28 So do not make the land vomit you out because you defile it just as it has vomited out the nations that were before you.

Leviticus 21:11

21:11 He must not go where there is any dead person; he must not defile himself even for his father and his mother.