On the Feast of Holy Pentecost, the Holy Church commemorates and glorifies the descent of the Holy Spirit upon the Apostles in the form of tongues of fire. The name “Pentecost” refers to the fact that this event took place on the 50^th day after the Christ’s salvific Resurrection. The Feast of Pentecost was also celebrated by the Old Testament Church, but that celebration was in commemoration of the fact that the Hebrews were handed down the Law [the Ten Commandments] on Mt. Sinai, fifty days after their exodus from Egypt....