Continuing the series first posted by me on the Catholica Forum.
NOTE: As with past commentaries, once again I must emphasise that the authors of the New Testament, and all the characters they depict, believed in the historicity of the major events of Israelite history. For instance, the entire theology of Paul is grounded in his belief in this historicity.
The Day of Pentecost
Pentecost (Hebrew Shavuot) was the name given by Greek-speaking Jews to the festival which occurred fifty days after the offering of the barley sheaf during the Passover feast.
"In Palestine the grain harvest lasted seven weeks and was a season of gladness (Jer. v. 24; Deut. xvi. 9; Isa. ix. 2). It began with the harvesting of the barley (Men. 65-66) during the Passover and ended with the harvesting of the wheat at Pentecost, the wheat being the last cereal to ripen. Pentecost was thus the concluding festival of the grain harvest, just as the eighth day of Tabernacles was the concluding festival of the fruit harvest (comp. Pesik. xxx. 193). According to Ex. xxxiv. 18-26 (comp. ib. xxiii. 10-17), the Feast of Weeks is the second of the three festivals to be celebrated by the altar dance of all males at the sanctuary..." 
The festival of Shavuot (Pentecost) is the traditional anniversary of the day on which God spoke at Sinai, which is believed to have occurred fifty days after the first paschal lamb was eaten on the eve of the Exodus from Egypt.
"When the day of Pentecost came, they were all together in one place. Suddenly a sound like the blowing of a violent wind came from heaven and filled the whole house where they were sitting. They saw what seemed to be divided tongues of fire that came to rest on each of them. All of them were filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them." (Acts 2:1-3)
In this and other passages in Acts, Luke draws on a wealth of Israelite tradition to make abundantly clear to his readers that this particular Shavuot represents a new Sinai:
Some biblical parallels...
"Mount Sinai was covered with smoke, because the LORD descended on it in fire." (Ex.19:18)
"The voice of the Lord divides the flames of fire. The voice of the Lord shakes the wilderness." (Psalm 29:7–8)
"He makes winds his messengers, flames of fire his servants." (Psalm 104:4)
"Our God comes, he does not keep silence, before him is a devouring fire, round about him a mighty tempest." (Psalm 50:3)
Luke goes on to draw further biblical parallels...
Compare the about 3000 destroyed in Ex. 32:28 with the about 3000 baptised in Acts 2:41.
Compare the representative twelve pillars for twelve tribes in Ex 24:4 with the representative twelve witnesses for twelve tribes of Acts 2:1-15.
Luke also draws on some non-biblical parallels...
The concept of "tongues of fire" appears in at least two Dead Sea Scrolls fragments. 
God's voice at Sinai divides into seventy tongues/languages.
Needless to say, all these parallels would have passed completely over the heads of non-Israelites.
The concern of Luke-Acts is totally focused on Israel.
For our purposes it is not necessary to go on and further analyse the traditional Israelite basis for the Pentecost experience but only to be aware of the identity of the parties who saw and heard what happened on that day.
The Twelve Witnesses...
Throughout the Synoptic Gospels, emphasis is placed on the fact that Jesus chose a core group of twelve men to proclaim the forthcoming reign of God to Israelites.
After Jesus' death and resurrection, the eleven remaining men of this core group are given the task of serving as witnesses to what the God of Israel has done to Jesus on Israel's behalf.
In Acts 1:15, we find Peter addressing a group of 120 "men," "brothers." The very first item on the agenda of this group is to appoint a replacement for Judas, who must be one of "the men who have accompanied us during all the time that the Lord Jesus went in and out among us, beginning from the baptism of John until the day when he was taken from us-one of these must become a witness with us to the resurrection." (Acts 1:21-22)
This first order of business underscores the importance Luke placed on the symbolism of there being twelve "witnesses," one for each of the twelve tribes of Israel. It is vital to recognise that these twelve "witnesses" were chosen because they had the necessary qualifications to offer first-hand authentication of Jesus' life from beginning to end. Peter's role was that of a first-hand witness. No first-hand witness can have a successor. Peter can have no successor.
Note: While some translations favour gender-inclusive language in 1:15, the substitution of words like "believers" and "friends" conceals the reason why Luke specifies that there were 120 "names" (persons) present, such reason being that each of the Twelve is affiliated with ten males, ten males being the number required to constitute an Israelite quorum.
"Now there were housed in Jerusalem Jews, pious men, from among all the non-Israelites (Gentiles) under the sky."
This verse refers to those ethnic-in-groups who follow the customs of the Jews of Judea and worship at the Temple in Jerusalem.
The remainder of the passage describes these Jews according to where they lived among non-Israelites i.e. Jewish Parthians, Jewish Medes, Jewish Elamites, Jewish Mesopotamians, Jewish Judeans and so on. (Jesus and the twelve were Jewish Galileans.)
The twelve stand and Peter begins his witness to the crowd by addressing them as "Men, Israelites". He finishes his witness thus:
"Therefore let the entire house of Israel know with certainty that God has made him both Lord and Messiah, this Jesus whom you crucified."
From Luke's account of Pentecost, we can determine the following:
- That Peter desired the "entire house of Israel" to know that the long-awaited Messiah of Israel had already been made manifest.
- That, for Luke, this day of Pentecost represented a new Sinai for the "entire house of Israel."
- That Luke went to considerable pains to demonstrate that this day of Pentecost was a uniquely Israelite experience drawn from uniquely Israelite traditions.
In summary, the Pentecost experience recorded in Acts was written to Israel, for Israel, about Israel. It would have had absolutely no meaning or relevance for non-Israelites (Gentiles).
We discovered from the historical sources given in Part VIII of this series that many of the dispersed of Israel were located in the very territories mentioned in Acts 2:9-11. We further discovered that the most influential, the most wealthy, and the most powerful of all the diaspora groups in the first century AD was located on the Mesopotamian plain, in Babylon and its surrounds.
I asked this question in Part V of this series:
"We have outlined above some objections to Peter's presence in Rome between 50 and 62 AD. So, if it were not westwards to Rome, where amongst the many communities of Diaspora Israelites would Peter have been most likely to go in furtherance of his personal commission by Jesus to preach the gospel to the "lost sheep of the House of Israel?"
The most reasonable answer to this question is that Peter would likely have travelled eastwards to the regions of Babylon on the Mesopotamian plain, where the great majority of these "lost sheep of the House of Israel" lived. Philo and Josephus both inform us that in the apostolic age, Babylonian Jews were very numerous and very wealthy and every year sent large amounts of silver and gold to the Temple in Jerusalem, whereas Jews were comparatively few in Rome, about eight thousand according to Josephus.
In the next commentary we will look at the 1st Epistle of Peter...
 1Q29; 4Q376 Liturgy of the Three Tongues of Fire
 Because Genesis states that seventy peoples came from the loins of Noah (Gen 10:11) and that a "mixed multitude" accompanied the Israelites out of Egypt (Ex 12:38), a legend developed that God's voice at Sinai divided itself into seventy tongues or languages. There are numerous references to seventy languages although it is now impossible to determine the time frame in which the legend began to develop. For a comprehensive view of these legends see Louis Ginzberg, The Legends of the Jews, tr. H. Szold, Philadelphia, 1964, Vol. 1, 62.
 Philo, Legatio ad Cajum, 36
 Josephus, Antiquities, XV.2.2; XXIII.12
 ibid XVII.2