They that gladly received his word were baptized. — This was, we must remember, no new emotion. Not four years had passed since there had been a like eagerness to rush to the baptism of John. (See Notes on Matthew 3:5; Matthew 11:12.)
Three thousand souls. — The largeness of the number has been urged as rendering it probable that the baptism was by affusion, not immersion. On the other hand, (1) immersion had clearly been practised by John, and was involved in the original meaning of the word, and it is not likely that the rite should have been curtailed of its full proportions at the very outset. (2) The symbolic meaning of the act required immersion in order that it might be clearly manifested, and Romans 6:4, and 1 Peter 3:21, seem almost of necessity to imply the more complete mode. The swimming-baths of Bethesda and Siloam (see Notes on John 5:7; John 9:7), or the so-called Fountain of the Virgin, near the Temple enclosure, or the bathing-places within the Tower of Antony (Jos. Wars, v. 5, § 8), may well have helped to make the process easy. The sequel shows (1) that many converts were made from the Hellenistic Jews who were present at the Feast (Acts 6:1); and (2) that few, if any, of the converts were of the ruling class (Acts 4:1). It is obvious that some of these converts may have gone back to the cities whence they came, and may have been the unknown founders of the Church at Damascus, or Alexandria, or Rome itself.