|Jews from all over were in Jerusalem|
Act 2:2 And suddenly a sound like a violent rushing wind came from heaven and filled the whole house where they were sitting.
Act 2:3 And divided tongues like fire appeared to them and rested on each one of them.
Act 2:4 And they were all filled with the Holy Spirit and began to speak in other languages as the Spirit gave them ability to speak out. LEB.
What excitement must have been in Jerusalem when Jews from all over the World had come to celebrate the Second of the Three obligatory Feasts. They were Act 2:9 Parthians and Medes and Elamites and those residing in Mesopotamia, Judea and Cappadocia, Pontus and Asia,
Act 2:10 Phrygia and Pamphylia, Egypt and the parts of Libya toward Cyrene, and the Romans who were in town, Act 2:11 both Jews and proselytes, Cretans and Arabs-- Jews from every nation under heaven.
THE FEAST OF PENTECOST ISBE says “As the name indicates (πεντηκοστή, pentēkostḗ), this second of the great Jewish national festivals was observed on the 50th day, or 7 weeks, from the Paschal Feast, and therefore in the Old Testament it was called “the feast of weeks.”#
It is but once mentioned in the historical books of the Old Testament (2Ch_8:12, 2Ch_8:13), from which reference it is plain, however, that the people of Israel, in Solomon's day, were perfectly familiar with it: “offering according to the commandment of Moses, on the sabbaths, and on the new moons, and on the set feasts, three times in the year, even in the feast of unleavened bread, and in the feast of weeks, and in the feast of tabernacles.”
The requirements of the three great festivals were then well understood at this time, and their authority was founded in the Mosaic Law and unquestioned. The festival and its ritual were minutely described in this Law. Every male in Israel was on that day required to appear before the Lord at the sanctuary (Exo_34:22, Exo_34:23). It was the first of the two agrarian festivals of Israel and signified the completion of the barley-harvest (Lev_23:15, Lev_23:16; Deu_16:9”, ISBE.
Exo_34:22; Num_28:26; Deu_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, Lev_23:17, Lev_23:20; Num_28:27-31.
So Imagine the 0ne hundred and Twenty waiting for the Holy Spirit as Jesus had directed them all praying in the Upper room on the Day of the Harvest Festival , the Day of Pentecost. The Lord had instructed them to wait in Jerusalem and they were all together in the Upper Room where Jesus had celebrated the Last Supper. Acts 1:14
The King James Version says, “2:1 when the day of Pentecost was fully come, they were all with one accord in one place. “ This says that they were all with ONE ACCORD or One Mind.
Adam Clark suggests, “With one accord, ὁμοθυμαδον; this word is very expressive: it signifies that all their minds, affections, desires, and wishes, were concentred in one object, every man having the same end in view; and, having but one desire, they had but one prayer to God, and every heart uttered it. There was no person uninterested - none unconcerned - none lukewarm; all were in earnest; and the Spirit of God came down to meet their united faith and prayer. When any assembly of God’s people meet in the same spirit they may expect every blessing they need.
1. We need united prayer and supplication for the Coming of the Holy Spirit. Note they were earnestly seeking and waiting for the Holy Spirit even on a National Holiday. They did not let anything interrupt their minds and hearts which were focused on the desired object.
2. What blessings occur when Brothers dwelling in unity. When they are united in search of one thing -The Blessing of Pentecost.