On this day in the year 351, not long after Cyril had succeeded Maximus as Archbishop of Jerusalem, during the reign of Constantius, the son of Saint Constantine the Great, on the day of Pentecost, the sign of the Cross appeared over Jerusalem. Saint Cyril, in his letter to the Emperor Constantius, says, At about the third hour of the day, an enormous Cross, formed of light, appeared in the heaven above holy Golgotha and reaching to the holy Mount of Olives. being seen not by one or two only, but manifest with perfect clarity to the whole multitude of the city; not, as one might suppose, rushing swiftly past in fancy, but seen openly above the earth many hours in plain sight, and overcoming the beams of the sun with its dazzling rays" (PG 33:1 16q).
Apolytikion in the First Tone
The image of Thy Cross at this time shone brighter than the sun, when Thou didst spread it out from the holy Mount of Olives to Calvary; and in making plain Thy might which is therein, O saviour Thou didst also thereby strenghten the faithful. Keep us always in peace, by the intercessions of the Theotokos, O Christ our God, and save us.
Kontakion in the Fourth Tone
Making its rays to shine above in the heavens, the spotless Cross dawned on the earth, bright with splendour; for it had opened Heaven, which was shut of old. Granted the effulgence of its divine operation, we are surely guided to the unwaning resplendence. In battles we possess it as a true weapon of peace and a trophy invincible.