9-11. Parthians, &c.—Beginning with the farthest east, the Parthians, the enumeration proceeds farther and farther westward till it comes to Judea; next come the western countries, from Cappadocia to Pamphylia; then the southern, from Egypt to Cyrene; finally, apart from all geographical consideration, Cretes and Arabians are placed together. This enumeration is evidently designed to convey an impression of universality [BAUMGARTEN].

     Ac 2:14-36. PETER FOR THE FIRST TIME, PUBLICLY PREACHES CHRIST.

     41-47. they that gladly received his word were baptized—"It is difficult to say how three thousand could be baptized in one day, according to the old practice of a complete submersion; and the more as in Jerusalem there was no water at hand except Kidron and a few pools. The difficulty can only be removed by supposing that they already employed sprinkling, or baptized in houses in large vessels. Formal submersion in rivers, or larger quantities of water, probably took place only where the locality conveniently allowed it" [OLSHAUSEN].