This comes from Psalm 117.1; all Gentiles and all peoples are used synonymously in this verse. In Greek the second imperative in this verse is a third person form (literally “let all peoples praise him”), but in English the full force of the form can only be expressed by means of a second person imperative: praise him, all peoples.

In many languages there is no such thing as a third person imperative. It may be necessary therefore to say: “All of you Gentiles praise the Lord; all of you people praise him very much.” Or a third person expression of obligation may be employed: “All Gentiles should praise the Lord, and all peoples should praise him very much.” All peoples may be translated in some languages as “all nations” or “all tribes.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on Paul’s Letter to the Romans. (UBS Handbook Series). New York: UBS, 1973. For this and other handbooks for translators see here .