Numbers 18:12

18:12 “All the best of the olive oil and all the best of the wine and of the wheat, the first fruits of these things that they give to the Lord, I have given to you.

Numbers 18:17

18:17 But you must not redeem the firstborn of a cow or a sheep or a goat; they are holy. You must splash their blood on the altar and burn their fat for an offering made by fire for a pleasing aroma to the Lord.