The day of Pentecost was the 50th day after the Sabbath of Passover week (Leviticus 23:15-16). It is also called the Feast of Harvest (Exodus 23:16), the day of firstfruits (Numbers 28:26) and the Feast of Weeks (Deuteronomy 16:10). It was an Israelite festival in which offerings were made to God, including the firstfruits of the wheat harvest.
The name “Pentecost” comes from the Greek πεντεκοστε and means the 50th day. The word first appears in the Bible in Acts 2:1, introducing the amazing events that occurred in Jerusalem on the first day of Pentecost after Jesus went to heaven.