The same principle applies to clean and unclean foods. It appears in Genesis 7:1-2, when Noah was filling up the ark. By the time we get to Leviticus, it was not new. It, too, I am sure, existed right from the very beginning.
How did Abel know to sacrifice a clean animal? Where does it appear? It appears way back at the beginning, just like the marriage and divorce law—that is, God&39;s intention. Then it is assigned in the laws in Leviticus and Deuteronomy. Again, in the New Testament we find Peter, in Acts 10, stoutly defending himself because nothing common or unclean—both of them—had ever passed his lips.