Acts 1:15
And in those days Peter stood up in the midst of the disciples, and said, (the number of names together were about an hundred and twenty,)
Cross-reference
Acts 21:20
Contrast
Acts 21:20 reports thousands of Jewish believers, contrasting the small beginning of 120 in Acts 1:15 and showing church growth.
Acts 2:41
Contrast
Acts 2:41 records 3,000 added — contrasting the initial 120 and showing rapid growth after Pentecost.
Matthew 13:31
Parallel
Matthew 13:31's mustard seed parable illustrates the kingdom starting tiny; Acts 1:15's 120 believers embody that small beginning.
Luke 22:32
Prophetic fulfillment
In Luke 22:32, Jesus prays for Peter's faith and tells him to strengthen his brothers. Here Peter fulfills that by standing up among the 120.
John 21:15–17
Allusion
In John 21:15-17, Jesus commissions Peter to feed His sheep. Acts 1:15 shows Peter leading the flock, fulfilling that commission.