John Chrysostom

"For even they shall be called," he says, "the children of the living God." But if they should assert that this was said of those of the Jews who believed, even then the argument stands. For if with those who after so many benefits were hard-hearted and estranged, and had lost their being as a people, so great a change was wrought, what is there to prevent even those who were not estranged after being taken to Him, but were originally aliens, from being called, and, provided they obey, from being counted worthy of the same blessings?

Homily on Romans 16 ↗

Theophylact of Ohrid

And even, what is more important, sons of the living God. If someone should say that this was spoken about the Jews who had conducted themselves ungratefully but were afterwards received into grace, such an argument does not harm our explanation. For if this acceptance happened with them, what prevented it from happening with the Gentiles?

Commentary on Romans ↗

Thomas Aquinas

Then, when he says and it shall be in the place, he cites another text from Hosea in which they are promised the dignity of being sons of God (Hos 1:10), about which the Jews boasted because, as it says in Isaiah: sons have I reared and brought up (Isa 1:2) and in Deuteronomy: is he not your father? (Deut 32:6). …

Commentary on Romans ↗