Acts 2:1

And when the day of Pentecost - The word “Pentecost” is a Greek word signifying the 50th part of a thing, or the 50th in order. Among the Jews it was a applied to one of their three great feasts which began on the 50th day after the Passover. This feast was reckoned from the 16th day of the month Abib, or April, or the second day of the Passover. The paschal lamb was slain on the 14th of the month at evening, Leviticus 23:5; on the 15th day of the month was a holy convocation - the proper beginning of the feast; on the 16th day was the offering of the firstfruits of harvest, and from that day they were to reckon seven weeks, that is, 49 days, to the feast called the Feast of Pentecost, so that it occurred 50 days after the first day of the Feast of the Passover. This feast was also called the Feast of Weeks, from the circumstance that it followed a succession of weeks, Exodus 34:22; Numbers 28:26; Deuteronomy 16:10. It was also a harvest festival, and was accordingly called the Feast of Harvest; and it was for this reason that two loaves made of new meal were offered on this occasion as first-fruits, Leviticus 23:17, Leviticus 23:20; Numbers 28:27-31.

Was fully come - When the day had arrived. The word used here means literally “to be completed,” and as employed here refers, not to the day itself, but to the completion of the interval which was to pass before its arrival (Olshausen). See Luke 9:51. Compare Mark 1:15; Luke 1:57. This fact is mentioned, that the time of the Pentecost had come, or fully arrived, to account for what is related afterward, that there were so many strangers and foreigners present. The promised influences of the Spirit were withheld until the greatest possible number of Jews should be present at Jerusalem at the same time, and thus an opportunity be afforded of preaching the gospel to vast multitudes in the very place where the Lord Jesus was crucified, and also an opportunity be afforded of sending the gospel by them into distant parts of the earth.

They were all - Probably not only the apostles, but also the 120 people mentioned in Acts 1:15.

With one accord - See Acts 1:14. It is probable that they had continued together until this time, and given themselves entirely to the business of devotion.

In one place - Where this was cannot be known. Commentators have been much divided in their conjectures about it. Some have supposed that it was in the upper room mentioned in Acts 1:13; others that it was a room in the temple; others that it was in a synagogue; others that it was among the promiscuous multitude that assembled for devotion in the courts of the temple. See Acts 2:2. It has been supposed by many that this took place on the first day of the week; that is, on the Christian Sabbath. But there is a difficulty in establishing this. There was probably a difference among the Jews themselves as to the time of observing this festival: The Law said that they should reckon seven sabbaths; that is seven weeks, “from the morrow after the sabbath,” Leviticus 23:15. By this Sabbath the Pharisees understood the second day of the Passover, on whatever day of the week it occurred, which was kept as a day of holy convocation, and which might be called a Sabbath. But the Karaite Jews, or those who insisted on a literal interpretation of the Scriptures, maintained that by the Sabbath here was meant the usual Sabbath, the seventh day of the week. Consequently, with them, the day of Pentecost always occurred on the first day of the week; and if the apostles fell in with their views, the day was fully come on what is now the Christian Sunday. But if the views of the Pharisees were followed, and the Lord Jesus had with them kept the Passover on Thursday, as many have supposed, then the day of Pentecost would have occurred on the Jewish Sabbath, that is, on Saturday (Kuinoel; Lightfoot). It is impossible to determine the truth on this subject. Nor is it of much importance. According to the later Jews, the day of Pentecost was kept also as a festival to commemorate the giving of the Law on Mount Sinai; but no trace of this custom is to be found in the Old Testament.