What does the Bible say about Pentecost?

Pentecost, as described in Acts 2, celebrates the outpouring of the Holy Spirit on the followers of Jesus, marking a significant transition from the old covenant of the law to the new covenant of grace. This event is rooted in the Jewish feast of the first fruits of the wheat harvest and commemorates the giving of the law to Moses at Sinai. When the Holy Spirit descended, it empowered the apostles to proclaim the Gospel in various languages, fulfilling the prophecy of Joel that God's Spirit would be poured out upon all flesh, indicating the dawn of a new dispensation in God's redemptive history.