Romans 15:9

9.The Gentiles also, (446) etc. This is the second point, on proving which he dwells longer, because it was not so evident. The first testimony he quotes is taken from Psalms 18:0; which psalm is recorded also in 2 Samuel 22:0, where no doubt a prophecy is mentioned concerning the kingdom of Christ; and from it Paul proves the calling of the Gentiles, because it is there promised, that a confession to the glory of God should be made among the Gentiles; for we cannot really make God known, except among those who hear his praises while they are sung by us. Hence that God’s name may be known among the Gentiles, they must be favored with the knowledge of him, and come into communion with his people: for you may observe this everywhere in Scripture, that God’s praises cannot be declared, except in the assembly of the faithful, who have ears capable of hearing his praise.

The quotation from Psalms 18:49, is verbatim from the Septuagint. The Hebrew verb with its postfix, אודך, in our version, “I will give thanks to thee,” may more properly be rendered, “I will confess thee.” — Ed.