H. P. Blavatsky

Mirror. The Luminous Mirror, Aspaqularia nera, a Kabbalistic term, means the power of foresight and farsight, prophecy such as Moses had. Ordinary mortals have only the Aspaqularia della nera or Non Luminous Mirror, they see only in a glass darkly: a parallel symbolism is that of the conception of the Tree of Life, and that only of the Tree of Knowledge. [w.w.w.].

Source: H. P. Blavatsky, The Theosophical Glossary, art. Mirror