John Chrysostom : Mark, here, I pray you, a character of teaching: "I kept back nothing," he says, ungrudging fulness, unshrinking promptness-"of what was profitable unto you:" because there were things which they did not need to learn. For as the hiding some things would have been like grudging, so the saying all things would be folly. This is why he adds, "that was profitable unto you. But have showed you, and have taught you:" have not only said, but also taught: not doing this either as a mere matter of form. For that this is what he means, observe what he says: "publicly, and from house to house:" thereby representing the exceeding toil, the great earnestness and endurance. — Homily on Acts 44