An heave — offering — An acknowledgment that they have all their land and the fruits of it from God's bounty. Note the word heave — offering, which is for the most part understood of a particular kind of offerings heaved or lifted up to the Lord, is here used for any offering.
Related Commentaries of Numbers 18:24
Numbers 18:24
24 But the tithes of the children of Israel, which they offer as an heave offering unto the LORD, I have given to the Levites to inherit: therefore I have said unto them, Among the children of Israel they shall have no inheritance.