13th century icon of Ss. Peter and Paul (
Having rejoiced for fifty days following
Pascha (Easter), the
Resurrection of Jesus Christ, the
Apostles began to prepare for their departure from
Jerusalem to spread Christ's message. According to
Sacred Tradition, as part of their preparation, they began a fast with prayer to ask God to strengthen their resolve and to be with them in their
The scriptural foundation for the Fast is found in the
Synoptic Gospels, when the
Pharisees criticized the apostles for not fasting, Jesus said to them, "Can the children of the bridechamber mourn, as long as the Bridegroom is with them? But the days will come, when the Bridegroom shall be taken from them, and then shall they fast."
 In the immediate sense, Christ was referring to his being taken to be
crucified; but in the wider sense it is understood in terms of his
Ascension into heaven, and his
commission to preach the
Gospel, which can only be accomplished with prayer and fasting.
The tradition of the Fast has existed at least since
Pope Leo I (461 AD), as is evidenced by his homilies,
 though it has subsequently been forgotten in the West. The Fast is thought to have been instituted out of thanksgiving to God for the witness of the apostles of Christ. With this Fast, believers express their thanks for the apostles' endurance of persecution during their mission.