4 “Who is like the Lord our God, that has His dwelling so high; and yet beholds the humble?”. Any one would think that He dwells in the lofty heavens, whence He may behold the humble things on earth; but “He beholds the humble things that are in heaven and earth”: what then is His high dwelling, whence He beholds the humble things that are in heaven and earth? Are the humble things He beholds His own high dwelling itself? For He thus exalts the humble, so as not to make them proud. He therefore both dwells in those whom He raises high, and makes them heaven for Himself, that is, His own abode; and by seeing them not proud, but constantly subject to Himself, He beholds even in heaven itself these very humble things, in whom raised on high He dwells. For the Spirit thus speaks through Isaiah: “Thus says the Highest that dwells on high, that inhabites eternity; the Lord Most High, dwelling in the holy.” He has expounded what He meant by dwelling on high, by the more full expression, “dwelling in the holy.”...
Source: The Enarrations, or Expositions, on the Psalms (New Advent)