Numbers 18:8, 19

Then the LORD spoke to Aaron, “Behold, I have given you charge of the contributions made to me, all the consecrated things of the people of Israel. I have given them to you as a portion and to your sons as a perpetual due.

All the holy contributions that the people of Israel present to the LORD I give to you, and to your sons and daughters with you, as a perpetual due. It is a covenant of salt forever before the LORD for you and for your offspring with you.”