Bhagavad Gita · Sankhya YogaChapter 2, Shloka 72 (2.72)

"Brāhmī sthiti" — two readings.

• Shankaracharya: sarvaṃ karma saṃnyasya brahma-rūpeṇaiva avasthānam — giving up all action and abiding as Brahman itself. Brahma-nirvana = brahma-nirvṛtiṃ mokṣam — supreme peace in Brahman, moksha. Madhusudana: gacchaty abhedena — he attains it as non-different; and the ignorance destroyed by knowledge cannot be born again, hence "na vimuhyati".
• Ramanujacharya: eṣā nityātma-jñāna-pūrvikā asaṅga-karmaṇi sthitiḥ — being established in unattached action, together with knowledge of the eternal self; brāhmī = brahma-prāpikā — that which leads to Brahman. "Na vimuhyati" = na punaḥ saṃsāram āpnoti — he does not return to samsara again. Brahma-nirvana = nirvāṇamayaṃ brahma — Brahman full of bliss — he attains sukhaikatānam ātmānam — the self whose nature is pure bliss.

That is, for Shankara this state is one of renunciation of action; for Ramanuja, of unattached action — each in keeping with his own doctrine.

"Antakāle 'pi" — even at the final hour. Shankaracharya and Ramanuja both take this in the sense of antye vayasi — the last stage (age) of life. Shankaracharya says: when even by being established in it in the last stage of life one attains brahma-nirvana, then kimu vaktavyam — what need be said of the person who takes sannyasa straight from brahmacharya and remains established in Brahman all his life! That is, "api" (even) — even starting late is not in vain.