Pentecost

When the Day of Pentecost had fully come, they were all with one accord in one place. And suddenly there came a sound from heaven, as of a rushing mighty wind, and it filled the whole house where they were sitting. Then there appeared to them divided tongues, as of fire, and one sat upon each of them. And they were all filled with the Holy Spirit and began to speak with other tongues as the Spirit gave them utterance.

Acts 2:1-4 New King James Version (NKJV)

Pentecost is a prominent feast in the calendar of Ancient Israel celebrating the giving of the Law on Mount Sinai. In the New Testament of the Holy Scriptures, during this wonderful celebration the Holy Spirit came upon 120 in the upper room after the Resurrection of our Savior Jesus Christ.   The meaning of Pentecost is fiftieth day. Pentecost is celebrated 50 days after Resurrection Day. (Easter) 

 (Holy Bible References, Leviticus 23:10-11, 15-17, Acts 2, John 16-5-15)