B.G 18.51-55

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.

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.