Romans 10:19

But I say, &c. Another objection is anticipated and met, (as indeed it has been already met, less explicitly,) viz., that Israel had no prophetic warningof the Gentiles" enlightenment and their own unbelief.

know? i.e. "know the prospect" of the spread of Messiah's Gospel, and their own rejection of it.

Moses saith Deuteronomy 32:21; verbatim with LXX. and Heb., except that "you" is substituted for "them," probably to make the reference unmistakable. The words occur in the sublime prophetic Song of Moses, so full of the mysterious future of both judgment and mercy for Israel. The point of the sentence (see the whole of the verse in Deut.) clearly is that the God of Israel would adopt other nationsas Israel had adopted other gods. The clause is more strictly rendered Moses is the first to say. But the difference is not important.

no people … a foolish nation i.e., probably, in the opinion of Israel. Israel had taken up deities despised of God; He would take up a people despised of Israel. At the same time the description would be true of the Gentiles in respect of their lack of previous privilege and revelation.