John Calvin on Acts 14:26

26. When they had been commended. Luke might have said that they were ordained there to be the apostles of the Gentiles; but by a circuit of words “Verborum circuitu,” by a circumlocution. he doth more plainly express that they were neither sent away of men, neither did they attempt any thing trusting to their own strength, but that their whole journey, together with the success, was committed to God, the author thereof. Therefore, their preaching was no man’s work, but a work of the grace of God. And the word grace is referred as well unto the power and efficacy of the Spirit, as also unto all the rest of the signs of favor; because all those gifts be free which God bestoweth upon his servants. And the sentence may be thus resolved, that they prayed God that he would show forth his grace to further the labors of his servants.