John Chrysostom

"Now we know that what things soever the Law saith, it saith to them who are under the Law." This then is why, next to Isaiah, who confessedly aimed at them, he brought in David; that he might show that these things also belonged to the same subject. For what need was there, he means, that a prophet who was sent for your correction should accuse other people. For neither was the Law given to any else than you. And for what reason did he not say, we know that what things soever the prophet saith, but what things soever the Law saith? …

Homily on Romans 7 ↗

Theophylact of Ohrid

Lest the Jews be able to object: this is not spoken to us, he declares: "the law, if it says anything, speaks to those who are under the law." What need, he says, is there to speak to others, when the law was given to you? By "law" he means the entire Old Testament, and not the law of Moses alone, just as now he called the prophecies of Isaiah and David "law." With the words "every mouth is stopped" he depicts the boasting of the Jews and the unstoppable impulse of their tongue. …

Commentary on Romans ↗

Thomas Aquinas

Then when he says now we know that what things soever, he explains the text he quoted in three ways: first, by expounding its sense; second, its intention, at that every mouth; third, he gives the reason for his words, at because by the works of the law. It should be noted that the Jews, against whom the Apostle was speaking, could, to excuse themselves, pervert the sense of the text he cited and claim that it referred to the gentiles, not to the Jews. …

Commentary on Romans ↗