The Bible has much to say about Pentecost, a Greek word identifying the conclusion of the Jewish harvest festival.
Jewish Harvest Festival
The origins of this feast come from the book of Exodus, when God asks for a feast to celebrate the “harvest of the first fruits.”
You shall also keep the feast of the grain harvest with the first fruits of the crop that you sow in the field.Exodus 23:16
It is also mentioned in the book of Leviticus, with more specific instructions.
Beginning with the day after the sabbath, the day on which you bring the sheaf for elevation, you shall count seven full weeks; you shall count to the day after the seventh week, fifty days. Then you shall present a new grain offering to the Lord.Leviticus 23:15-16
The feast of Pentecost is also called the, “the feast of weeks.”
Descent of the Holy Spirit
It was on the celebration of this Jewish festival that the Holy Spirit descended upon the apostles, marking the “birthday” of the Church.
When the time for Pentecost was fulfilled, they were all in one place together. And suddenly there came from the sky a noise like a strong driving wind, and it filled the entire house in which they were. Then there appeared to them tongues as of fire, which parted and came to rest on each one of them.Acts 2:1-3
In this way the Christian celebration of Pentecost takes on a new meaning, highlighting the role of the Holy Spirit in the life of the Church.