Halakhah su Levitico 19:25

From the laws of the commandment is that which they, may their memory be blessed, said (Berakhot 35a) that one who wants to redeem the fourth year plant, redeems it like the second tithe, which [can be] redeemed - meaning to say, that he redeems it with money and brings [that] up to Jerusalem. And if he redeems it himself, he adds a fifth. As so is the law with the second tithe, from that which it is written about it (Leviticus 27:31), "And if a man surely redeems his tithes." But one who redeems the second tithe for others, does not add a fifth. And he does not redeem [the fourth year plant] until it reaches the season of the tithe; as it is stated about it (Leviticus 19:25), "to increase its produce for yourselves" - and they, may their memory be blessed, expounded (Sifra, Kedoshim, Section 3:10), "Until it becomes produce" - meaning to say that it reaches the season of the tithe, and that is a third of its ripeness. And according to Rambam (Mishneh Torah, Laws of Second Tithes and Fourth Year's Fruit 9:2), may his memory be blessed, we do not redeem it when it is attached [to the tree], like the tithe. But others explain (Rash on Orlah 5:5) that we redeem it even attached. And it is called money of the Higher Realm, like the tithe. And therefore it cannot be acquired as a gift - unless he gave it when it is still unripe fruit, as the obligation has not yet rested upon it, as we said. And its law in the other things - such as eating, drinking and anointment - is like the tithe. And on the commandment of the second tithe in Parshat Reeh Anochi (Sefer HaChinukh 473), we will write more about it at length with God's help.