John Chrysostom

"Then Paul and Barnabas waxed bold, and said, It was necessary that the word of God should first have been spoken to you: but seeing ye put it from you, and judge yourselves unworthy of everlasting life, lo, we turn to the Gentiles." Do you mark how by their contentious behavior they the more extended the preaching, and how the Apostles here gave themselves the more to the Gentiles, having by this very thing pleaded their justification, and made themselves clear of all blame with their own people at Jerusalem? …

Homily on Acts 30 ↗

Theophylact of Ohrid

So that the words "you make yourselves unworthy of eternal life" might not be interpreted by someone as evidence of their humility, Paul first said "as you reject it." Then he added "we turn to the Gentiles." He does not say "we are leaving you," but expresses himself in such a way that allows for the possibility of his return to Antioch.

Commentary on Acts ↗

Oecumenius

He did not think that what is said was unseemly of modesty and shame, that you judged yourselves unworthy; therefore he prefaced, You reject that: and then he adds: We turn to the Gentiles. But he did not say: We abandon you, but that it might be possible that we should again, he says, be turned towards you here. [CHRYSOSTOM]

Commentary on Acts ↗