B.G 18.51-55

बुद्ध्या विशुद्धया युक्तो धृत्याऽऽत्मानं नियम्य च। शब्दादीन् विषयांस्त्यक्त्वा रागद्वेषौ व्युदस्य च ॥५१॥

विविक्तसेवी लघ्वाशी यतवाक्कायमानसः। ध्यानयोगपरो नित्यं वैराग्यं समुपाश्रितः ॥५२॥

अहङ्कारं बलं दर्पं कामं क्रोधं परिग्रहम्। विमुच्य निर्ममः शान्तो ब्रह्मभूयाय कल्पते ॥५३॥

ब्रह्मभूतः प्रसन्नात्मा न शोचति न काङ्क्षति। समः सर्वेषु भूतेषु मद्भक्तिं लभते पराम् ॥५४॥

भक्त्या मामभिजानाति यावान् यश्चास्मि तत्त्वतः। ततो मां तत्त्वतो ज्ञात्वा विशते तदनन्तरम् ॥५५॥

With intellect purified, engaged with determination, controlling oneself, and abandoning sensory objects like sound, one discards attachment and aversion; one who enjoys solitude, is a moderate eater, controlled in speech, body, and mind, is always devoted to meditation and yoga, and has fully embraced dispassion; having abandoned ego, strength, pride, desire, anger, and possessiveness, and who is free from the sense of ownership and is peaceful, is eligible to attain the state of abiding in Brahman. A person who is realized in Brahman, with a pleased mind, neither laments nor desires anything. Being equally disposed to all beings, such a person attains My supreme devotion. Through devotion, he knows me, how much and who I am in reality. Then, having known me in reality, he enters that afterwards.

Gīta Bhāshya 18.51-55

'brahmabhūyāya' - being in a constant state of mindfulness and abiding in Brahman.

ब्रह्मभूयाय कल्पते - ब्रह्मणि भावः ब्रह्मभूयम्। ब्रह्मणि स्थितिः सर्वदा तन्मनस्कतेत्यर्थः ॥५३॥

In the term 'brahmabhūyāya kalpate', 'brahmabhūyāya' means the state of being in Brahman; it means being in a constant state of mindfulness and abiding in Brahman.

Gīta Tātparya 18.51-55

Having conducted oneself by the method being explained, thereafter, having perfected the art of performing actions that leave no-imprints, having reached the state of being in tune with Brahman, in the presence of goddess Mahalakshmi, i.e. Cit-Prakrti, how one attains liberation is explained.
'vimucya nirmamaḥ śāntaḥ' i.e. "Having become free, without attachment, peaceful" - means having attained 'naiṣkarmyasiddhiṁ', i.e. 'the perfecting the art of performing actions that does not leave imprints', one becomes 'brahmabhūyam' i.e. 'brahmaṇi bhūyāya' i.e. 'capable of residing in Brahman'.

वक्ष्यमाणप्रकारेण वर्तमानः तदनन्तरं नैष्कर्म्य सिदि्धं प्राप्तो भूत्वा ब्रह्माख्यायाः महालक्ष्म्याः सकाशं यथा प्राप्नोति तथा निबोध।

Having conducted oneself by the method being explained, thereafter, having obtained the perfection of performing actions that leave no-imprints, having reached the state of being in tune with Brahman, in the presence of goddess Mahalakshmi, i.e. Cit-Prakrti, how one attains liberation is explained.

मम योनिः र्महद् ब्रह्म" "ब्रह्मणो हि प्रतिष्ठाहम्" इत्युक्तत्वात् "ब्रह्मभूतः प्रसन्नात्मा" इत्युक्त्वा "मद्भक्तिं लभते पराम्" इति वक्ष्यमाणत्वाच्च।

"My womb is the 'mahat', i.e. Cit-Prakrti", "Indeed, I am the foundation of Universe" - having said this, it is also said "One who has become in tune with Brahman, with a serene mind", "attains supreme devotion to me."

"सर्वपापक्षयाद् देहं त्यक्त्वा देवान् क्रमाद् व्रजन्। प्राप्य लक्ष्मीं तत्प्रसादात् पुनः स्वृद्धा हरौ यदा। भक्तिस्तया पुनर्ज्ञाने स्वृद्धे विष्णुं प्रपद्यते। अपरोक्षदृशो विष्णोः शरीरेऽपि सतः पुरा॥ त्यक्तदेहादिकस्यापि यावद्विष्णुं प्रपद्यते। तावद्गुणा विवर्धन्ते स्थिताः स्युः प्राप्य केशवम्॥"

"After destroying all sins and leaving the body, one gradually ascends to the gods. By the grace of Lakshmi, one becomes prosperous in Hari. With further accumulation of devotion and knowledge, one surrenders to Vishnu. Even in the body one was formerly in existence, one obtains a direct vision of Vishnu. Even for one who has abandoned the body and others, until he surrenders to Lord Viṣṇu, his qualities increase and remain until he attains Lord Keśava."

इति महावराहे॥

- stated thus in the great Varāha Purana.

"विमुच्य निर्ममः शान्तः" नैष्कर्म्यसिदि्धं प्राप्तो भूत्वा ब्रह्मणि भूयाय भवतीत्यर्थः॥

"vimucya nirmamaḥ śāntaḥ" i.e. "Having become free, without attachment, peaceful" - means having attained 'naiṣkarmyasiddhiṁ', i.e. perfecting the art of performing actions that does not leave imprints, one becomes 'brahmabhūyam' i.e. 'brahmaṇi bhūyāya' i.e. 'capable of residing in Brahman'.