Luke
Acts 9:23BSB·traditional attribution

After many days had passed, the Jews conspired to kill him,

John Calvin Reformed @genevareformer

23. When many days were fulfilled. He saith that many days were expired, that we may know that Paul had some space of time granted him wherein he might do good. For although the Jews did resist him even from the first day, yet the Lord did not suffer the course which he had begun well to be broken off so soon, so he doth...

Matthew Henry Presbyterian @wholebiblehenry

Luke here makes no mention of Paul's journey into Arabia, which he tells us himself was immediately after his conversion, Gal 1:16, Gal 1:17. As soon as God had revealed his Son in him, that he might preach him, he went not up to Jerusalem, to receive instructions from the apostles (as any other convert would have done, that was designed for the ministry), but...

Commenting on Acts 9:23-31

John Gill Reformed Baptist @doctorgill

And after that many days were fulfilled,.... This phrase is used by the Septuagint on Exo 2:11 for a considerable length of time, for many years. The Jewish writers observe (t), that the phrase, "many days", signify at least three days; for by "days", in the plural number, two must be designed, and many signifies a third, or that one at least is added to...