Leviticus 18:30
"Therefore shall ye keep mine ordinance, that ye commit not any one of these abominable customs, which were committed before you, and that ye defile not yourselves therein: I am the LORD your God."
Cross References (ranked by relevance)
Leviticus 20:23
And ye shall not walk in the manners of the nation, which I cast out before you: for they committed all these things, and therefore I abhorred them.
Leviticus 22:9
They shall therefore keep mine ordinance, lest they bear sin for it, and die therefore, if they profane it: I the LORD do sanctify them.
Deuteronomy 11:1
Therefore thou shalt love the LORD thy God, and keep his charge, and his statutes, and his judgments, and his commandments, alway.