Sabbath day for sabbath, A.V.; we went forth without the gate for we went out of the city, A.V. and T.R. ( πύλης for πολέως); we supposed there Was a place of prayer for prayer was wont to be made, A.
V.; were come together for resorted thither, A.V. By a river side. By the river side is the natural way of expressing it in English. The river is not the Strymon, which is a day's journey distant from Philippi, but probably a small stream called the Gangas or Gangites, which is crossed by the Via Eguatia, about a mile out of Philippi.
The neighborhood of water, either near a stream or on the seashore, was usually preferred by the Jews as a place for prayer, as affording facility for ablutions (see Josephus, 'Ant. Jud.,' 14.10, 23; and other passages quoted by Alford).
The phrase, οὖ ἐνομίζετο προσευχὴ εἷναι, should be rendered, not as in the R.V., but more nearly as the A.V., where a prayer-meeting(of the Jews) was accustomed to be held; i.e. this particular spot was the usual place where such Jews or proselytes as happened to be at Philippi met for prayer.
It also appears from Epiphanius (' Hear.,' 80, § 1, quoted by Alford) that the Jews usually had their προσευχαί, whether buildings, or open spaces, ἔξω πολέως, outside the city. The wayside crosses are of the nature of προσευχαί.