The following account is a translation from the the Life of Saint Andrew the Fool which describes his vision of the Mother of God at the Church of Blachernae in Constantinople, for which the feast of the Protection of the Mother of God (October 1 or 28) is based on.
When a night-long doxology was held in the Holy Soros at Blachernae blessed Andrew was in attendance, behaving in his usual way. Epiphanios was also present, and with him one of his servants. Blessed Andrew was wont to stand there as long as his zeal gave him strength, sometimes until midnight, sometimes until morning. When it was already the fourth hour of the night he saw the Most Holy Theotokos appear in full sight, very tall, from the Royal Doors, escorted by an awe-inspiring retinue in which there were, among others, the Honorable Forerunner and the Son of Thunder, holding her by the hand on both sides, and many other holy men in white robes accompanied her, some going before her, others following her, singing hymns and spiritual songs.
As she approached the ambo the blessed man went up to Epiphanios and said: "Do you see the Lady and Mistress of the world?" He answered: "Yes, my spiritual father." And before their eyes she knelt and prayed for a long while, besprinkling with tears her godlike and all-immaculate face. Having finished her prayer she went into the sanctuary, praying there for the people standing around. When she had prayed, with beautiful dignity she removed her veil which she wore on her all-immaculate head, which appeared like a flash of lightning, and took it in her all-immaculate hands - it was large and awe-inspiring - and spread it over all the people that were standing there. For a long while the admirable men saw it stretched over the people, radiating the glory of the Lord like amber. As long as the Most Holy Theotokos was there the veil was also visible, but when she had withdrawn they could no longer see it. No doubt she had taken it away with her, but her grace she left to those who were there.