Numbers 18:11-13

This also is yours: the contribution of their gift, all the wave offerings of the people of Israel. I have given them to you, and to your sons and daughters with you, as a perpetual due. Everyone who is clean in your house may eat it. All the best of the oil and all the best of the wine and of the grain, the firstfruits of what they give to the LORD, I give to you. The first ripe fruits of all that is in their land, which they bring to the LORD, shall be yours. Everyone who is clean in your house may eat it.