How I kept back nothing that was profitable. — The verb is one which belongs to the vocabulary of sailors, and was used for taking in or reefing sails. He, St. Paul seems to say of himself, had used no such reticence or reserve, but had gone on his course, as it were, before the wind, with all his canvas spread. It must be noted, however, that even here, as in the more limited range of teaching imparted to the Corinthians (1 Corinthians 3:1-2), he confines his statement to the things that were “profitable.” In each case he considered what was required by the capacity of his disciples. That of Ephesus was wider than that of Corinth, and there, accordingly, he was able to set forth “the whole counsel of God” (Acts 20:27).
Publicly, and from house to house. — The first word points probably to the teaching in the synagogue and the lecture-room of Tyrannus (Acts 19:9), the second to the meetings of disciples which were held in private houses, such as that of Aquila and Priscilla (1 Corinthians 16:19). It may, however, include even more personal and individual counsel.