MĀṆḌŪKYA UPANISHAD · 9

जागरितस्थानो वैश्वानरोऽकारः प्रथमा मात्राऽऽप्तेरादिमत्त्वाद्
वाऽऽप्नोति ह वै सर्वान् कामानादिश्च भवति य एवं वेद ॥ ९॥

jāgaritasthāno vaiśvānaro’kāraḥ prathamā mātrā’’pterādimattvād
vā’’pnoti ha vai sarvān kāmānādiśca bhavati ya evaṃ veda ॥ 9॥

The Waker, Vaiswanor, the Universal Male, He is A, the first letter, because of Initiality and Pervasiveness; he that knoweth Him for such pervadeth and attaineth all his desires; he becometh the source and first.