The interpretation timeline
Acts 16:13 Douay-Rheims

And upon the sabbath day, we went forth without the gate by a river side, where it seemed that there was prayer; and sitting down, we spoke to the women that were assembled.

A.D. 407 – 1871 6 witnesses 7 excerpts

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“See again Paul judaizing. "Where it was thought," it says, both from the time and from the place, "that prayer would be." Out of the city, by a river side: for it is not to be supposed that they prayed only where there was a synagogue; they also prayed out of synagogue, but then for this purpose they set apart, as it were, a certain place, because as Jews they were more corporeal - and, "on the sabbath-day," when it was likely that a multitude would come together. "And we sat down, and spake to the women which resorted thither." Mark again the freedom from all pride. "Out of the city." The place was convenient for hearing the word, aloof from troubles and dangers. "On the sabbath." As there was no work going on, they were more attentive to what was spoken.”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And on the sabbath,.... That is, as the Syriac version renders it, "on the sabbath day"; the Jewish sabbath, the seventh day of the week; though the words may be rendered, "on a certain day of the week" agreeably to Act 20:7 where the first of the sabbath means the first day of the week; but be this as it will, on this day, we went out of the city by a river side; perhaps the river Strymon, which was near; the Alexandrian copy and some others, and the Vulgate Latin version read, without the gate; and the Syriac version, "without the gates of the city"; all to the same sense: it looks as if there was no synagogue of the Jews in this place, or otherwise the apostle and his companions would have gone into that, according to their custom; and this the rather seems to be the case, since it is so particularly remarked, that at Thessalonica, the next place they stayed at there was one, Act 17:1 and the reason might be, because that Philippi being a Roman colony, the Jews were not suffered to have one in it; wherefore Paul and his company, whether on the Jewish sabbath, or on any other day of the week, took a walk out of the city; either for the sake of a walk, or rather to converse together, and consider what was to be done, or to look out for an opportunity to preach the Gospel; and they came to a place, where prayer was wont to be made; or as the words may be rendered, "where was thought to be a place of prayer"; a "proseucha", an oratory, or a place built and made use of for prayer; that is, as they walked along, they saw a place, which in their opinion looked like a religious house, or a place for prayer, and so made up to it, where they found some persons assembled together on that account: this sense is confirmed by several versions; the Vulgate Latin version reads, "where there seemed to be prayer", and so reads Beza's most ancient copy; and the Syriac version is very express, "for there was seen" , "an house of prayer"; to which agrees the Arabic version, "we went out to a certain place, which was thought to be a place of prayer"; to which may be added the Ethiopic version, "and we thought there was prayer there"; and that the Jews had their oratories, or prayer houses, is certain; See Gill on Luk 6:12 and that these were without the cities, and in the fields, appears from a passage of Epiphanius (f), who says, "there were anciently places of prayer, both among the Jews, "without the city", and among the Samaritans, there was a place of prayer at Sichem, which is now called Neapolis, "without the city", in the field, about two stones distance, in form of a theatre, open to the air, and without covering, built by the Samaritans, who in all things imitated the Jews:'' and if these were commonly built by fountains and rivers, and as some think, in imitation of Isaac, who went out into the field, "to meditate"; which the Chaldee paraphrase renders, "to pray"; and is also in the same place said to come, as the Jerusalem paraphrase renders it, "to a well", or "fountain", Gen 24:62 then this clause may be rendered, "where it was usual for a prayer house to be": and then the sense is, there being no synagogue in the city, the apostle and those with him went out of it, to the river side, to look out for a prayer house; where such places were wont to be built, and they accordingly found one: and we sat down, and spake unto the women which resorted thither; who seem to have been Jewish women, who met here to attend public prayer, there being no religious worship of the true God in the city; and among these worshippers of God was Lydia, hereafter mentioned; and worship not being begun, the apostle and his companions sat down among them, and entered into some religious conversation with them, and took the opportunity of preaching the Gospel, which was what they wanted, and were seeking after. (f) Contr. Haeres. Tom. 2. l. 3. Haeres. 80.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“By a river side, where prayer was wont to be made - Οὑ ενομιζετο προσευχη ειναι, where it was said there was a proseucha. The proseucha was a place of prayer, or a place used for worship, where there was no synagogue. It was a large building uncovered, with seats, as in an amphitheatre. Buildings of this sort the Jews had by the sea side, and by the sides of rivers. See this subject considered at large in the note on Luk 6:12 (note). It appears that the apostles had heard from some of the Gentiles, or from some of the Jews themselves, that there was a place of prayer by the river side; and they went out in quest of it, knowing that, as it was the Sabbath, they should find some Jews there. Spake unto the women - Probably this was before the time of their public worship, and while they were waiting for the assembling of the people in general; and Paul improved the opportunity to speak concerning Christ and salvation to the women that resorted thither.”
Source
1849
A.D.
1774–1849
“There was prayer. [1] The Greek word signifies either prayer itself, or an oratory, or place to pray in. (Witham) — Not every prayer is here understood, but that which was joined in the celebration of the sacred mysteries. (Estius, in different location.) See 1 Corinthians vii. and Acts vi.”
1863
A.D.
1796–1863
“It is thought to mean a place of prayer — a grove by the shore, in which they were wont to assemble. The Jews used to assemble for prayer near the river banks. See Philo in Flacc. Joseph. Antiq. 1. xiv. c. x. § 24.”
“We know not how it happened that women only were assembled. Bloomfield conjectures that each sex had a separate hour of prayer, as there was probably no division in the oratory, or there may have been no building whatever.”
1871
A.D.
1871
“on the sabbath day--the first after their arrival, as the words imply. we went out of the city--rather, as the true reading is, "outside of the (city) gate." by a river-side--one of the small streams which gave name to the place ere the city was founded by Philip of Macedon. where prayer was wont to be made--or a prayer-meeting held. It is plain there was no synagogue at Philippi (contrast Act 17:1), the number of the Jews being small. The meeting appears to have consisted wholly of women, and these not all Jewish. The neighborhood of streams was preferred, on account of the ceremonial washings used on such occasions. we sat down and spake unto the women, &c.--a humble congregation, and simple manner of preaching. But here and thus were gathered the first-fruits of Europe unto Christ, and they were of the female sex, of whose accession and services honorable mention will again and again be made.”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.