Read Romans 15:9 Using Other Translations
And that the Gentiles might glorify God for his mercy; as it is written, For this cause I will confess to thee among the Gentiles, and sing unto thy name.
and in order that the Gentiles might glorify God for his mercy. As it is written, "Therefore I will praise you among the Gentiles, and sing to your name."
He also came so that the Gentiles might give glory to God for his mercies to them. That is what the psalmist meant when he wrote: “For this, I will praise you among the Gentiles; I will sing praises to your name.”