Pentecost is a significant Christian holiday commemorating the descent of the Holy Spirit upon Mary, the mother of Jesus, and his apostles. It occurs 49 days after Easter and is observed in various Christian denominations. The term "Pentecost" originates from the Greek word "pentēkostē," meaning "fiftieth," and has its roots in the festival of Shavuot in Judaism. The events of Pentecost are described in the New Testament in the Acts of the Apostles, where the disciples "...were filled with the Holy Spirit and began to speak in other tongues..." Acts 2:4. This event is regarded as the fulfillment of Christ's promise to baptize his followers with the Holy Spirit. https://en.wikipedia.org/wiki/Pentecost