Praise God, all ye Gentiles, etc. This passage is not inaptly applied; for how can they, who know not God's greatness, praise him? They could no more do this than to call on his name, when unknown. It is then a prophecy most suitable to prove the calling of the Gentiles; and this appears still more evident from the reason which is there added; for he bids them to give thanks for God's truth and mercy. (Psalm 117:1.)

And again - Psalm 117:1. The object in this quotation is the same as before. The apostle accumulates quotations to show that it was the common language of the Old Testament, and that he was not depending on a single expression for the truth of his doctrine.
All ye Gentiles - In the psalm, "all ye nations;" but the original is the same.
And laud him - "Praise" him. The psalm is directly in point. It is a call on "all" nations to praise God; the very point in the discussion of the apostle.

And again,.... It is written in Psalm 117:1,
praise the Lord all ye Gentiles, and laud him all ye people; that is, praise him both Jews and Gentiles, for his merciful kindness and truth, as in Romans 15:2; the Gentiles for his mercy in choosing, redeeming, and calling them, as before; and the Jews for his truth and faithfulness in the fulfilment of his praises. R. David Kimchi on this psalm observes, that
"it consists of two verses only, and that it belongs , "to the days of the Messiah"; and intimates, by the composition of it in two verses only, that all people shall be divided into two parts, or be on two sides, Israel shall be in their law, and all the nations in seven precepts,''
i.e. of Noah.

And again-- (Psalm 117:1).
Praise the Lord, all ye Gentiles; and laud him, all ye people--"peoples"--the various nations outside the pale of Judaism.

Psalm 117:1.