Bhagavad Gita · Jnana Karma Sannyasa YogaChapter 4, Shloka 10 (4.10)

Three purifications, one refuge. (1) The departure of attachment, fear and anger; (2) man-maya — a consciousness absorbed in the Lord; (3) mām upāśritāḥ — refuge; and the means — jñāna-tapas (the austerity of knowledge).

Shankaracharya: man-mayāḥ brahmavidaḥ īśvarābheda-darśinaḥ — knowers of Brahman who see their non-difference from the Lord; mām eva ca parameśvaram upāśritāḥ kevala-jñāna-niṣṭhāḥ (taking refuge in me alone, the Supreme Lord, steadfast in knowledge alone); jñānam eva ca paramātma-viṣayaṃ tapaḥ — knowledge of the Supreme Self is itself austerity; mad-bhāvam īśvara-bhāvaṃ mokṣam — my state, that is, the state of the Lord, liberation. The qualifier "jñāna-tapasā" shows that this is itara-tapo-nirapekṣa jñāna-niṣṭhā — steadfastness in knowledge that does not depend on other austerities. And the next question: do you have attachment and aversion, that you grant oneness with yourself only to some? — the answer is 4.11.

Acharya Ramanuja: madīya-janma-karma-tattva-jñānākhyena tapasā — through the austerity that is knowledge of the truth of my birth and deeds, many have been purified. He quotes the Upanishad — tasya dhīrāḥ parijānanti yonim — only the steadfast (the foremost of the wise) know the manner of his birth.