John Calvin Commentary Acts 18:15

"but if they are questions about words and names and your own law, look to it yourselves; I am not minded to be a judge of these matters." — Acts 18:15 (ASV)

Of words and names. These words are not well arranged. Yet Gallio speaks this way of the law of God contemptuously, as if the Jewish religion consisted only of words and superfluous questions. And surely (as that nation was very prone to contention) there is no doubt that many troubled themselves and others with superfluous trifles. Indeed, we hear how Paul sharply rebukes them in many places, especially in the Epistle to Titus (Titus 1:14, and Titus 3:9).

Yet Gallio, who mocks the holy law of God along with their curiosity, cannot be excused. For just as it was his duty to put an end to all opportunity for useless arguments about words, so we, on the other hand, must recognize that when the worship of God is at stake, the conflict is not merely about words, but a matter of utmost seriousness is being addressed.