9 And whence were you fed? And what pleased you, when he did not eat with you? “My eyes,” he says, “were upon such as are faithful in the land, that they might sit with me”. That is, that with Me they might be seated. In what sense are they “to sit”? “You shall sit on twelve thrones, judging the twelve tribes of Israel.” The faithful of the earth judge, for to them it is said, “Do you not know, that we shall judge angels?” “Whoso walks in a spotless way, he ministered unto me.” To “Me,” he says, not to himself. For many minister the Gospel, but unto themselves; because they seek their own things, not the things of Jesus Christ....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)