מדרש אויף תהילים 49:8

And when He said: When shall they give every man a ransom for his soul (Exod. 30:12), he wondered and said: Who is able to give a ransom for his soul, since it is said: No man can by any means redeem his brother, nor give to God a ransom for him, for too costly is the redemption of their soul (Ps. 48:8–9)? He replied: It is not as you imagine. This they shall give indicates that they shall give something like this. R. Huna said in the name of Rab: The Almighty, whom we cannot find out, is excellent in power (Job 37:23) implies that the Holy One, blessed be He, did not impose impossible burdens upon Israel. When Moses realized that he declared: Happy is the people that is in such a case (Ps. 144:15) and Happy is he whose help is the God of Jacob (ibid. 146:5).

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."

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."