Luke
Acts 19:8ESV·traditional attribution

And he entered the synagogue and for three months spoke boldly, reasoning and persuading them about the kingdom of God.

John Calvin Reformed @genevareformer

8. Going into the synagogue. By this we gather that Paul began with the company of the godly, who had already given their names to Christ. Secondly, that he came into the synagogue, that he might gather together into one body of the Church the rest of the Jews who knew not Christ as yet, or at least who had not as yet received him.

Matthew Henry Presbyterian @wholebiblehenry

Paul is here very busy at Ephesus to do good. I. He begins, as usual, in the Jews' synagogue, and makes the first offer of the gospel to them, that he might gather in the lost sheep of the house of Israel, who were now scattered upon the mountains. Observe, 1. Where he preached to them: in their synagogue (Act 19:8), as Christ used to do.

Commenting on Acts 19:8-12

John Gill Reformed Baptist @doctorgill

But when divers were hardened and believed not,.... For though some were affected with and convinced by the arguments the apostle used, others were but the more hardened and remained incredulous: for the Gospel, while it is the savour of life unto life to some, it is the savour of death unto death, to others; as the sun melts the wax, and hardens the clay...