★ Synaxis of the holy archangel Gabriel
The synaxis of the holy archangel Gabriel is celebrated by the Orthodox Church on 13 July, in addition to its principal observance on 26 March, the day after the Annunciation. This second feast was instituted on the Holy Mountain of Athos in the ninth century, in the reign of the emperor Basil and the empress Constantina Porphyrogenitus, during the patriarchate of Nicholas Chrysoverges, in commemoration of a remarkable miracle worked by the archangel near the cell of an elder at Karyes.
According to the ancient account, an aged ascetic and his disciple lived in a cell dedicated to the Dormition near Karyes. One Saturday evening the elder departed for the all-night vigil at the church of the Protaton, leaving the disciple alone to keep his prayer rule. While he was singing the canon to the Mother of God, an unknown monk arrived and joined him in the chanting. When they came to the ninth ode and the disciple began the irmos "More honourable than the cherubim," the visiting monk sang first a different opening: "It is truly meet to bless you, the Theotokos, ever blessed and most pure, and the mother of our God." On hearing these words, the icon of the Mother of God in the cell shone with a wonderful light, and the disciple, marvelling, asked the stranger to write the verses down so that he might remember them.
Finding no paper or ink at hand, the stranger took up a stone slab and inscribed the words upon it with his finger as easily as if it had been wax. He then revealed himself as the archangel Gabriel, charged him to sing the hymn in this manner, saying, "And let all the Orthodox sing it likewise," and at once vanished from sight. The slate was carried in solemn procession to the Protaton and thence to Constantinople, and from that time the hymn Axion Estin has been chanted in the Divine Liturgy throughout the Orthodox Church. The icon before which the angel sang is also called the Axion Estin and is kept to this day in the sanctuary of the Protaton on Mount Athos.