But when they believed Philip.... — The word for preaching is, as in Acts 8:4, “preaching the glad tidings of the kingdom of God.” The sequel shows that this included baptism as the outward condition of admission to the kingdom. We may infer from the other narrative of Philip’s mission-work (Acts 8:31-35) that it also included an outline-history of the passion and death and resurrection of the Prophet whom they had seen among them as fulfilling the great Messianic prophecies.
They were baptized, both men and women. — The tense points, not to one great act, but to the continual succession of converts who were thus admitted. We think of the woman of Samaria, of John 4:7, and wonder whether she was one of them.