Leviticus 22:28-30

Amplified Bible

²⁸ And whether [the mother] is a cow or a sheep, you shall not kill both it and its young in one day. ²⁹ When you sacrifice an offering of thanksgiving to the Lord, you shall sacrifice it so that you may be accepted. ³⁰ It shall be eaten on the same day; you shall leave none of it until the next morning; I am the Lord.