Numbers 18:11-13

And this is thine; the heave offering of their gift, with all the wave offerings of the children of Israel: I have given them unto thee, and to thy sons and to thy daughters with thee, by a statute for ever: every one that is clean in thy house shall eat of it. All the best of the oil, and all the best of the wine, and of the wheat, the firstfruits of them which they shall offer unto the LORD, them have I given thee. And whatsoever is first ripe in the land, which they shall bring unto the LORD, shall be thine; every one that is clean in thine house shall eat of it.