1 “O praise the Lord, all you heathen: praise Him, all you nations”. These are the courts of the Lord's house, this all His people, this the true Jerusalem. Let those rather listen who have refused to be the children of this city, since they have cut themselves off from the communion of all nations. “For His merciful kindness is ever more and more towards us: and the truth of the Lord endures for ever”. These are those two things, loving-kindness and truth, which in the CXVth Psalm I admonished you should be committed to memory. But “the merciful kindness of the Lord is ever more and more towards us,” since the furious tongues of hostile nations have yielded to His Name, through which we have been freed: “and the truth of the Lord endures for ever,” whether in those things which He promised to the righteous, or in those which He has threatened to the ungodly.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)