Pentecost

Pentecost is named here as the watershed moment just ahead — after it, the practice of casting lots disappears entirely because the Spirit dwelling within believers replaces the need for it.

Pentecost is invoked here as a founding Jewish festival, underscoring how thoroughly Jewish the early movement's origins were before this chapter's breakthrough.

Pentecost is the Jewish harvest festival that drew pilgrims from across the known world to Jerusalem, providing the massive multinational audience that witnessed and heard the Spirit's arrival.

Pentecost is the Jerusalem festival driving Paul's tight travel schedule — he wants to arrive in the city by this particular date, which is why he bypasses Ephesus rather than stopping.

Pentecost is the immediate backdrop to this chapter — the explosive event that launched the movement and set the stage for everything Peter and John are about to do.

Pentecost is the reference point for understanding what happens in Samaria — the Spirit's arrival here mirrors the founding event of the church, signaling that Samaritans receive the same gift on equal footing.