Starters from Fr. Tony Kadavil:
Pentecost literally means 50th. It is a feast celebrated on the 50th day after the Passover feast by the Jews and a feast celebrated on the 50th day after the feast of the Resurrection of Jesus by the Christians. The Jewish Pentecost was originally a post- harvest thanksgiving feast. Later it was celebrated to remember God’s covenants with Noah after the Deluge and with Moses at Mt. Sinai