Matthew Poole and continuators on Leviticus 27:21

21 But the field when it goeth out in the Jubile, shall be holy unto the LORD, as a field devoted: the possession thereof shall be the priests .

(i. e.) Out of the possession of the other man to whom the Priest sold it.

For their maintenance. Nor is this repugnant to that law, that the Priests should have no inheritance in the land, Numb. 18. 20. for that is onely spoken of them and the whole Tribe of Levi in general and in reference to the first division of the land, wherein the Levites were not to have a distinct part of land, as other tribes had, but this doth not hinder but some particular lands might be vowed and given to the Priests either for their own benefit or for the service of the Sanctuary.