Midrash su Levitico 27:24

7) (Vayikra 27:24) "In the Yovel year the field shall return to the one from whom it was bought": I might think, to the Temple treasurer, from whom it was bought (by the last purchaser); it is, therefore, written "to the one who has the holding in the land (i.e., the original owner). (In that case let it be written [only] "to the one who has the holding in the land." Why state "to the one from whom it was bought'? (For I might think that) a field which went out to the Cohanim on the Yovel and was sold by the Cohein (who acquired it), and was consecrated by the buyer — I might think that when the second Yovel arrived, it reverted to the original owner (whose field of holding it was before he consecrated it); it is, therefore, written "to the one from whom it was bought" (namely, the Cohein who sold it, [as opposed to the original owner, who consecrated it]). (Vayikra 27:25) ("And all of your valuations (concerning which it is written "shekalim") shall be according to the shekel of the sanctuary; twenty gerah shall the shekel be.") "And all of your shekels shall be according to the shekel of the sanctuary": There is no valuation less than a sela (the same as a shekel). "according to the shekel of the sanctuary": What is the intent of this? Because it is written (Vayikra 27:27) "and he shall redeem," I might think, with servants, deeds, and land; it is, therefore written "with the shekel of the sanctuary." This tells me only of the shekel of selaim of the sanctuary. Whence do I derive for inclusion anything that is (of monetary value and is) movable? From "and he shall redeem." If so, why is it written "with the shekel of the sanctuary"? To exclude servants, deeds, and land.

8) "twenty gerah shall the shekel be": Whence is it derived that if he wishes to increase (the value of the shekel), he may do so? From "shall be" (connoting the possibility of a change). I might then think that if he wishes to decrease (the value) he may do so. It is, therefore, written (Bamidbar 20:6) "It is (twenty gerah"), (i.e., at least twenty gerah).

(Exodus 21:30) "When kofer is imposed upon him, he shall give the redemption of his soul": the value of the victim. These are the words of R. Yishmael. R. Akiva says: the value of the killer (i.e., the owner of the ox). And thus do we find that redemption is not given for those who are put to death. In all places, those who are liable to death at the hands of man are not redeemed, as it is written (Leviticus 27:24) "Any cherem that is devoted from a man (going out to be executed) shall not be redeemed, (for) he is going to be put to death" (and has no valuation). But here "he shall give the redemption of his soul." R. Yishmael says: Come and see the mercies of the One who spoke and brought the world into being, for flesh and blood. For a man acquires himself with money from the hands of Heaven, as it is written (Numbers 30:12) "When you take the sum of the children of Israel according to their number, then each man shall give the ransom of his soul to the L rd, etc.", and (II Kings 12:5) "each man, the money for the valuation of his soul," and (Mishlei 13:8) "A man's wealth may redeem his soul," and (Daniel 4:24) "But, O king, let my counsel be acceptable to you. Redeem your soul through charity," and (Job 33:23-24) "If there will be for him but a single defending angel from a thousand to declare a man's uprightness for him, then He will be gracious to him and He will say: Redeem him from descending to the grave I have found kofer for Him!" We find that certain consecrated objects can be redeemed and others cannot be redeemed; certain things that may not be eaten may be redeemed; things from which benefit may not be derived may not be redeemed. The nations of the world cannot be redeemed, as it is written (Psalms 49:8) "A man cannot redeem his brother; he cannot give his kofer to G d. Too costly is their soul's redemption and unattainable forever." Beloved is Israel for whose souls the Holy One Blessed be He has given the nations as kofer, as it is written (Isaiah 43:3) "I gave Egypt as kofer for you." Why? (Ibid. 4) "Because you were honored in My eyes, you were honored and I loved you, and I placed a man in your place and nations in place of your souls."