Sapphire Mystic Sky, A Noetic Height Somewhat Resembling the Sky’s Hue
"The fifth sign of the working in you of the Spirit... consists in the illuminated vision of your mind, which is seen in the firmament of your heart like the sapphire sky."
-- Joseph Hazzaya, also known as Joseph the Visionary or Joseph the Seer, translated from Syriac Aramaic by Alphonse Mingana, Woodbrooke Studies, Volume Seven: Early Christian Mystics: https://archive.org/details/Mingana1934WoodbrookeStudiesVol.7
“The rays of primordial Light that illumine purified souls with spiritual knowledge not only fills them with benediction and luminosity; they also, by means of contemplation of the inner essences of created things, lead them up to the Noetic heavens. For this reason Saint Neilos says, ‘The intellect’s proper state is a noetic height, somewhat resembling the sky’s hue, which is filled with the Light of the Holy Trinity during the time of prayer.’”
-- The Philokalia, Volume IV, writings of Greek Saints: https://archive.org/details/PhilokaliaTheCompleteTextPhilokaliaCompleteText/page/n1/mode/2up/search/The+Philokalia?q=The+Philokalia