Shankara Digvijaya by Madhava Vidyaranya is the biography of Adi Shankaracharya.
That Consciousness which shines forth most distinctly in waking, dream, and deep sleep; that which is the one Witness of the universe that threads all bodies ranging from Brahma’s down to the ant’s; that I am, and not anything phenomenal — whoever possesses this firm wisdom is my guru, be he a chandala or a person twice-born. This is my conviction.
I and this whole universe are but Brahman, a manifestation of pure Consciousness; all these phenomena have been imagined by me through ignorance comprising the three gunas. He whose mind is thus firmly rooted in the supremely blissful, eternal, pure, transcendental Reality is my guru, be he a chandala or a person twice-born. This is my conviction.
One who having realized, through the instructions of the guru, the utter unreality of the whole universe, engages oneself in the contemplation of the eternal Brahman with an honest calm mind, and burns up all sins, past and future, in the fire of Consciousness – (such a person) has submitted the body to prarabdha karma. This is my conviction.
The yogi whose mind is tranquil due to constant contemplation on the effulgence of the pure Consciousness existing in lower animals, humans, and gods as the ‘I’ within; by whose lustre shine forth the mind the senses, the body, and the objects of the senses, all void of consciousness in themselves; and which, like the sun, is covered by the very objects that it illumine — such a person is my guru. This is my conviction.
He whose mind is merged in that eternal ocean of Bliss — even the smallest part of a drop of which satisfies Indra and others, realizing which, through a totally unagitated mind, a sage becomes happy — such a person is himself Brahman and not (a mere) knower of Brahman. He is a worthy soul at whose feet the best of the gods bow down. This is my conviction.
The above five verses are famous as Manisha Panchakam.