Leviticus 27:32-34

³²One of every ten domestic animals belongs to me. When a shepherd counts his animals MTY to decide which ones he will give to me, he must mark every tenth one as belonging to me.

³³When he does that, he must not pick out the good ones for himself or leave the bad ones, or substitute bad ones for good ones. If he substitutes one animal for another, both animals will belong to me, and he will not be permitted to buy them back (OR, the shepherd cannot buy them back).' ”

³⁴Those are the commands that Yahweh gave to Moses/me on Sinai Mountain to tell to the people.