John Chrysostom

"For as ye in times past have not believed God, yet have now obtained mercy through their unbelief; even so have these also now not believed, that through your mercy they may also obtain mercy. For God hath concluded them all in unbelief, that He might have mercy upon all." He shows here that those of the Gentiles were called first. Then, as they would not come, the Jews were elected, and the same result occurred again. For when the Jews would not believe, again the Gentiles were brought over. …

Homily on Romans 19 ↗

Theophylact of Ohrid

You, he says, who were formerly called Gentiles, did not wish to obey: therefore the Jews were chosen and received the law. Again, when the Jews were called and did not obey Christ, you were chosen and shown mercy.

Commentary on Romans ↗

Thomas Aquinas

Then when he says, for as you also, he gives the reason for the future salvation of the Jews after their unbelief. First, he shows a similarity between the salvation of both people; second, the cause of this similarity, at for God has concluded. First, therefore, he says: so I say that Israel will be saved, although they are now enemies. …

Commentary on Romans ↗