On May 8th, the Eastern Church celebrates the synaxis in honor of the ashes or Holy "Manna" produced by the tomb of the holy and illustrious apostle and evangelist, the virgin and beloved disciple of Christ, the friend who leaned upon his chest at the Last Supper, and to whom the Virgin Mary was particularly entrusted: John "the Theologian."
Sometime after the burial of the holy Apostle John the Theologian at Ephesus (celebrated every year on the 26th of September), the disciples opened the grave, but found his tomb empty, and it became a source of miracles. On May 8th, it used to be covered with a kind of ashes, which the local Christians called "Manna." This substance could cure diseases of the soul and the body, for those who anointed themselves with faith.
Because of this annual miracle, the Church instituted a feast to celebrate the beloved disciple of the Lord and beloved son of the Mother of God.
According to the Orthodox Monastery