And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance. (Acts 2:4)
God gave the Feast of Weeks, a.k.a. Shavu’ot, (Leviticus 23:15-22) as the fourth of the Feasts of the Lord and the last of the spring feasts. God gave seven feasts to be observed as holy (i.e., set apart, consecrated, dedicated) convocations where all males over the age of 20 were required to attend. Later in their history, the Jews added Purim to celebrate their divine preservation in Babylon/Persia (Esther 9:20-32) and Chanukah, the Festival of Lights, to celebrate the rededication of the Temple after Antiochus IV Epiphanes desecrated it in 165 B.C.
Read more ... https://erniecarrasco.com/2017/05/28/pentecost/