yaḥ — who (King Pratīha); ātma-vidyām ākhyāya — after instructing many people about self-realization; svayam — personally; saṁśuddhaḥ — being very advanced and purified in self-realization; mahā-puruṣam — the Supreme Personality of Godhead, Viṣṇu; anusasmāra — perfectly understood and always remembered.
King Pratīha personally propagated the principles of self-realization. In this way, not only was he purified, but he became a great devotee of the Supreme Person, Lord Viṣṇu, and directly realized Him.
The word anusasmāra is very significant. God consciousness is not imaginary or concocted. The devotee who is pure and advanced realizes God as He is. Mahārāja Pratīha did so, and due to his direct realization of Lord Viṣṇu, he propagated self-realization and became a preacher. A real preacher cannot be bogus; he must first of all realize Lord Viṣṇu as He is. As confirmed in Bhagavad-gītā (4.34), upadekṣyanti te jñānaṁ jñāninas tattva-darśinaḥ: “One who has seen the truth can impart knowledge.” The word tattva-darśī refers to one who has perfectly realized the Supreme Personality of Godhead. Such a person can become a guru and propound Vaiṣṇava philosophy all over the world. The paragon of bona fide preachers and gurus is King Pratīha.