Numbers 18:28

So you shall also present a contribution to the Lord from all your tithes , which you receive from the people of Israel . And from it you shall give the Lord ’s contribution to Aaron the priest .

In this way you also will present an offering to the Lord from all the tithes you receive from the Israelites. From these tithes you must give the Lord`s portion to Aaron the priest.

Thus ye also shall offer an heave offering unto the Lord of all your tithes, which ye receive of the children of Israel; and ye shall give thereof the Lord's heave offering to Aaron the priest.