Adam Clarke on Leviticus 25:23

The land shall not be sold for ever - the land is mine - As God in a miraculous manner gave them possession of this land, they were therefore to consider themselves merely as tenants to him; and on this ground he, as the great landholder or lord of the soil, prescribes to them all the conditions on which they shall hold it. This one circumstance was peculiarly favorable to their advancement in religion, in righteousness, and true holiness; for feeling that they had nothing which they could call their own upon earth, they must frequently, by this, be put in mind of the necessity of having a permanent dwelling in the heavenly inheritance, and of that preparation without which it could not be possessed.