Again, it says: “Rejoice, O Gentiles, with His people.”
10 Exult, ye Gentiles, with his people This verse is commonly considered as if it was taken from the song of Moses; but with this I cannot agree; for Moses’ design there was to terrify the adversaries of Israel by setting forth his greatness, rather than to invite them to a common joy.
The apostle here returns to his exhortation to Christians. What he says here (Rom 15:7) is to the same purport with the former; but the repetition shows how much the apostle's heart was upon it. "Receive one another into your affection, into your communion, and into your common conversation, as there is occasion." He had exhorted the strong to receive the weak (Rom 14:1), here...
Commenting on Romans 15:7-12
And again,.... It is written in Psa 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 Rom 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.