8 There are some who rely on their friends, others rely on their virtue, others on their riches. This is the presumption of mankind which relies not on God. He has spoken of virtue, he has spoken of riches, he speaks of friends. “Brother redeems not, shall man redeem?”. Do you expect that man shall redeem you from the wrath to come? If brother redeem you not, shall man redeem you? Who is the brother, who if He has not redeemed you, no man will redeem? It is He who said after His resurrection, “Go, tell My brethren.” Our Brother He has willed to be: and when we say to God, “Our Father,” this is manifested in us.
For he that says to God, “Our Father;” says to Christ, “Brother.” Therefore let him that has God for his Father and Christ for his Brother, not fear in the evil day. “For the iniquity of his heel shall not compass him;” for he relies not on his virtue, nor glories in the abundance of his riches, nor vaunts himself of his powerful friends. Let him rely on Him who died for him, that he might not die eternally: who for his sake was humbled, in order that he might be exalted; who sought him ungodly, in order that He might be sought by him faithful. Therefore if He redeem not, shall man redeem? Shall any man redeem, if the Son of man redeem not? If Christ redeem not, shall Adam redeem? “Brother redeems not, shall man redeem?”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)