John Gill Bible Commentary

And if he will not redeem the field,.... He that sanctified it, does not care to give for it the settled price of the fifth part besides, but chooses it should be disposed of for the uses he devoted it to: or if he have sold the field to another man; that is, either the original owner having bought it and sold it again, or rather the priest, the treasurer, as Jarchi, who had the disposal of it, for the uses and purposes for which it was devoted, when sold by him: it shall not be redeemed any more; it was not in the power of him that sanctified it to make a purchase of it again; the buyer of it might not sell it to him again, for otherwise, by that means, he might come at it cheaper than the law directs; besides, there is another reason for it, which is suggested in Lev 27:21.