Albert Barnes Commentary Acts 16:13

"And on the sabbath day we went forth without the gate by a river side, where we supposed there was a place of prayer; and we sat down, and spake unto the women that were come together." — Acts 16:13 (ASV)

And on the sabbath. There is no doubt that in this city there were Jews. In the time of the apostles, they were scattered extensively throughout the known world.

By a river side. What river this was is not known. It is known, however, that the Jews were accustomed to provide water, or to build their synagogues and oratories near water, for the convenience of the numerous washings before and during their religious services.

Where prayer. This means where there was a proseuchae, or place of prayer, or where prayer was commonly offered. The Greek term supports either meaning, but the sense is the same. Places for prayer were established by the Jews near cities and towns, especially where there were not enough Jewish families, or where they were forbidden by the magistrate to build a synagogue. These proseuchae, or places of prayer, were simple enclosures made of stones, perhaps in a grove or under a tree, that offered a secluded and suitable place for worship.

Was wont. Was accustomed to be offered; or where it was established by custom.

And spake unto the women, etc. This was probably before the regular service of the place commenced.