This is the same Light that Moses experienced on Mt. Sinai when he encountered the Burning Bush. It is referred to in Orthodox Theology as The Uncreated Divine Light
Since we are discussing some new found information about the supernatural experiences of the Elder Porphyrios, I would like to first share with you what happened to him on Mt. Athos when he was a young monk. This is taken from one of the books that I translated about his life entitled “Testimonies and Experiences of the Elder Porphyrios.” This was published in 2007 by the Monastery he built in Malakasa, Greece. As quoted from this book: “We should not find it strange that Divine Grace should rest upon this young monk who was filled with fire for Christ and gave everything for His love. He never once considered all his labors and struggles an imposition upon his life.
It was still dawn, and the main Church of Kavsokalyvia was locked. Nikitas (Porphyrios before his tonsure), however, was standing in the corner of the Church entrance waiting for the bells to ring and the doors to be opened. He was followed by the old monk Dimas, a former Russian officer, over ninety years old, a holy ascetic man. Fr. Dimas looked around and made sure that nobody was there. He didn’t notice young Nikitas (Porphyrios) waiting in the shadows of the entrance. Fr. Dimas started making full genuflections and praying before the closed Church doors.