Feast of the Transfiguration
And it came to pass about an eight days after these sayings, he took Peter and John and James, and went up into a mountain to pray. And as he prayed, the fashion of his countenance was altered, and his raiment was white and glistering. And, behold, there talked with him two men, which were Moses and Elias: Who appeared in glory, and spake of his decease which he should accomplish at Jerusalem. But Peter and they that were with him were heavy with sleep: and when they were awake, they saw his glory, and the two men that stood with him. And it came to pass, as they departed from him, Peter said unto Jesus, Master, it is good for us to be here: and let us make three tabernacles; one for thee, and one for Moses, and one for Elias: not knowing what he said. While he thus spake, there came a cloud, and overshadowed them: and they feared as they entered into the cloud. And there came a voice out of the cloud, saying, This is my beloved Son: hear him. And when the voice was past, Jesus was found alone. And they kept it close, and told no man in those days any of those things which they had seen. (Luke 28-36)
The Feast seems to have originated in the churches of the East with the Latin Church being slow to adopt it. It is not mentioned before 850 and was not mandated for the whole Catholic Church until 1456 when Pope Callixtus III used it to mark the victory gained by John Hunyady at Belgrade over the Turks. On this day the pope at Mass uses new wine or presses a bunch of ripe grapes into the chalice; raisins are also blessed at Rome. The Greeks and Russians bless grapes and other fruit.
Though the name of the mountain is not given in the Gospels, the Transfiguration has become associated with Mount Tabor.