Mahabharata 1.1.20

सूत उवाच · sūta uvāca

आद्यं पुरुषमीशानं पुरुहूतं पुरुष्टुतम्ऋतमेकाक्षरं ब्रह्म व्यक्ताव्यक्तं सनातनम्

ādyaṃ puruṣamīśānaṃ puruhūtaṃ puruṣṭutamṛtamekākṣaraṃ brahma vyaktāvyaktaṃ sanātanam

Our plain-language meaning of this verse is waiting for scholar review.