How did Peter and the Holy Spirit coordinate when the Holy Spirit would fall upon them?
They didn't. Peter had his mouth open and "was still
speaking these words" (Acts 10:44) when "the Holy
Spirit fell upon all those who heard the word" (Acts 10:44).
This should be a lesson to any preacher today who thinks he can command the
Holy Spirit to do anything, especially on his cue. The Holy Spirit is God
and He does what He wills, to whom He wills, when He wills.
What was Peter in the midst of saying when the Holy Spirit fell on
the audience?
"Whoever believes in Him will receive remission of sins." (Acts 10:43)
Why might the Holy Spirit have chosen that moment to fall upon Cornelius and his company?
Perhaps because after meandering a bit, Peter had finally shared how the Gospel
relates to them.
Who were "those of the circumcision" (Acts 10:45)?
The Jewish Christian "brethren from Joppa" (Acts
10:23) who "came with Peter" (Acts 10:45).
Why were they "astonished" (Acts 10:45)?
Peter had been prepared in a vision for the breaching of the wall between
Jews and gentiles, but the Jewish believers who accompanied him had not been so
prepared. In that context, they (1) enter the house of a gentile, probably
for the first time in their lives; (2) hear Peter declare that God accepts
people from "every nation" (Acts 10:35); and then
(3) witness "the gift of the Holy Spirit" being
poured out on the gentiles, who "speak with tongues and magnify God"
(Acts 10:47), so they had a lot to take in.
Does Peter take the time to explain things and calm their astonishment?
No, he tells them
instead to fetch water and help their new brethren express their faith through water baptism.
What did they do thereafter?
They stayed and fellowshipped for "a few days"
(Acts 10:48). The love of Jesus had removed generations-old animosity and prejudice.
When is the last time you stayed with or invited into your
home a Christian from another social class, race or country?