David Bentley Hart

 For Sufi thought, God is the Self of all selves, the One—al-Ahad—who is the sole true 'I' underlying the consciousness of every dependent 'me.' According to the Kena Upanishad, Brahman is not that which the mind knows like an object, or that the eye sees or the ear hears, but is that by which the mind comprehends, by which the eye sees, by which the ear hears; atman—the self in its divine depth—is the eye of the eye, the ear of the ear, the ground of all knowing."