During the day he managed a patrician's household and daily went to the palace, engaged in worldly affairs, so that no one was aware of his pursuits. …One day, as he stood and recited, "God, have mercy upon me, a sinner" Lk. 18:13), uttering it with his mind rather than his mouth, suddenly a flood of divine radiance appeared from above and filled all the room. As this happened the young man lost all awareness [of his surroundings] and forgot that he was in a house or that he was under a roof. He saw nothing but light all around him and did not know if he was standing on the ground. He was not afraid of falling: he was not concerned with the world nor did anything pertaining to men and corporeal beings enter his mind. Instead, he seemed to himself to have turned into light. Oblivious of all the world he was filled with tears and with ineffable joy and gladness. His mind then ascended to heaven and beheld yet another light, which was clearer than that which was close at hand. In a wonderful manner there appeared to him standing close to that light, the saint of whom we have spoken, the old man equal to angels, who had given him the commandment and the book. …

(Saint Symeon the New Theologian)