John Chrysostom

"And he drave them from the judgment-seat"--he effectually closed the tribunal against them. "Then all having seized Sosthenes the ruler of the synagogue, beat him before the judgment-seat. And Gallio cared for none of these things": but their beating him he did not take as an insult to himself. So petulant were the Jews. This thing, of all others, set them on to this violence--their persuasion that the governor would not even let himself down to notice it. It was a splendid victory. O the shame they were put to! …

Homily on Acts 39 ↗

Theophylact of Ohrid

"And all the Greeks, having seized Sosthenes." As for the fact that they beat Sosthenes, this was either because he too, like Crispus the ruler of the synagogue, was more devoted to Paul, or they had already gone so far in their frenzy that, forgetting their plans, they began beating Sosthenes instead of Paul, or they beat him because they wanted to kill Paul, but Sosthenes did not allow them to. …

Commentary on Acts ↗

Oecumenius

Either for this reason they struck Sosthenes, since he too was more attached to Paul, as also Crispus the chief ruler of the synagogue; or they had been driven to such a degree of madness that, having failed in their purpose, instead of striking Paul they struck Sosthenes the chief ruler of the synagogue. Or: for this reason they struck him, because they were more eager to kill Paul, and Sosthenes prevented them. [AMMONIUS]

Commentary on Acts ↗

Bede

And all of them seized Sosthenes, the ruler of the synagogue, and beat him before the tribunal. In Greek it is better written: And all the Greeks seized Sosthenes. For after the Jews were disgracefully expelled from the tribunal, the Gentiles also afflicted their leader with greater humiliation by beating him.

Retractions on Acts ↗