I used to think that the Holy Spirit came upon the disciples in visible form as tongues of fire while they were gathered in the upper room. This impression may have come from a Bible story book, a Sunday School lesson or some other illustration. It seems a common impression.
I now have serious doubts about that picture. For one thing, Acts 1:15 tells us that the number of disciples wan one hundred and twenty. Was there an upper room somewhere with enough room for such a crowd? There were women in that number. Does it seem likely that a mixed group of men and women would gather in the living quarters of the apostles? (Verse 13). If they were somewhere in a residential area, how did a crowd of thousands suddenly gather around them?
The gospel of Luke ends with these words: “And were continually in the temple, praising and blessing God. Amen.” (Luke 23:43). Acts 2:46 says: “And they, continuing daily with one accord in the temple, and breaking bread from house to house, did eat their meat with gladness and singleness of heart.” Their meeting place was in the temple, not the upper room.
I think the problem was that I understood the temple to consist only of the building where the sacrifices and ceremonies took place. I now understand that there was a huge walled courtyard around three sides of this building and this courtyard was considered part of the temple. Other groups met for prayer in the courts of the temple, benches were provided for such meetings. No doubt the disciples designated a certain place in the courts as their meeting place.
“And when the day of Pentecost was fully come, they were all with one accord in one place” (Acts 2:1). The wording here is so close to Luke 23:43 and Acts 2:46 that there should be little doubt the place where they were gathered “with one accord” was the temple. This explains how it was possible for a crowd to gather around them almost immediately.
There is significance also in that the birth of the church, the new people of God, took place in the holy place of the old people of God. This temple would be destroyed before many more years had passed, but the people of God would continue to exist, in a new form.
“The sun shall be turned into darkness, and the moon into blood, before that great and notable day of the Lord come” (Acts 2:20). Matthew Henry and Adam Clarke understand Peter’s use of this prophecy from Joel to refer to the eclipse of the light of the Old Covenant kingdom. Both the civil and the sacred light of the Jewish nation were about to be extinguished, and the light of the gospel would shine over all the world.