5 And he has moved us also to enquire whether the Lord our God beholds the same humble things in heaven and in earth: or different humble things in heaven to what He beholds on earth....But if the Lord our God beholds other humble things in heaven to what He does on earth; I suppose that He already beholds in heaven those whom He has called, and in whom He dwells; while on earth He beholds those whom He is now calling, that He may dwell in them. For He has the one with Him musing on heavenly things, the others He is waking, while they yet dream things earthly.
But since it is difficult to call even those humble, who have not as yet submitted their necks in piety to the gracious yoke of Christ, since the divine writings throughout the whole Psalm warn us to understand holy by the word humble; there is also another interpretation, which, Beloved, you may consider with me. I believe that those are now meant by heavens who shall sit upon twelve thrones, and shall judge with the Lord; and under the name of the earth, the rest of the multitude of the blessed, who shall be set on the right hand, that through works of mercy they may be praised and received into everlasting habitations by those whom they have made friends to themselves from the mammon of unrighteousness in this mortal life....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)