אַל־תִּֽטַּמְּא֖וּ בְּכָל־אֵ֑לֶּה כִּ֤י בְכָל־אֵ֙לֶּה֙ נִטְמְא֣וּ הַגּוֹיִ֔ם אֲשֶׁר־אֲנִ֥י מְשַׁלֵּ֖חַ מִפְּנֵיכֶֽם׃
Defile not ye yourselves in any of these things; for in all these the nations are defiled, which I cast out from before you.
Read kabbalistic (mystical) interpretation of Leviticus 18:24: and classical mystical sources.