Luke
Acts 13:2ESV·traditional attribution

While they were worshiping the Lord and fasting, the Holy Spirit said, “Set apart for me Barnabas and Saul for the work to which I have called them.”

John Calvin Reformed @genevareformer

2 And they ministered to the Lord. The word which Luke useth doth not only signify to be occupied about holy things, but also sometimes to bear public offices. And because the holy rites of the Gentiles did for the most part consist upon [of] burnt-offerings and sacrifices, it is oftentimes taken for to offer sacrifice; which sense did well like the Papists, that they...

Matthew Henry Presbyterian @wholebiblehenry

We have here a divine warrant and commission to Barnabas and Saul to go and preach the gospel among the Gentiles, and their ordination to that service by the imposition of hands, with fasting and prayer. I. Here is an account of the present state of the church at Antioch, which was planted, Act 11:20. 1.

Commenting on Acts 13:1-3

John Gill Reformed Baptist @doctorgill

As they ministered to the Lord,.... That is, the five prophets and teachers before mentioned; and whose ministry lay in preaching the Gospel, teaching the people the doctrines of it, and expounding prophecies, and also in prayer; to which latter the Syriac version restrains their ministry, rendering it, "as they prayed to God"; but the phrase seems to be more extensive: "and fasted"; which the...