Many marvels wert reported to occur in the Church of the Resurrection. Theodorus (or Theodosius, as he is also called), in 530 A.D., was told that the holy lance, which had been made into a cross, "shone at night like the sun by day." St. Silvia, says that at the early morning service no lights were brought into the church, but that they were supplied from an ever-burning lamp within the Cave of the Sepulchre. This seems to be the germ of the later "holy fire," which appeared at Easter, as first clearly described by Bernard the Wise,² who tells us that on the eve of Easter Day the "Kyrie eleison" was sung until the angel came to light the lamps. In the twelfth century the fire appeared sometimes in the Hospital of St. John or in the Temple enclosure in the cathedral, and was said to pass by an underground passage between the two latter. Is 1192 Saladin is said to have attendedthe ceremony, but the Saracens "asserted that it was a fraudulent contrivance."3 ...

Cited: Colonel C R Conder, The City of Jerusalem - History - 2004 - 376 p. P. 13.

2. Bernard (867 A.D.) "...."

3. Theodoricus (c. 1172 A.D.); Geof. De Vinsauf, t. 16.