B.G 8.01, 02, 03

अर्जुन उवाच,
किं तद्ब्रह्म किमध्यात्मं किं कर्म पुरुषोत्तम। अधिभूतं च किं प्रोक्तमधिदैवं किमुच्यते ॥१॥

What is that Brahman? What is the self (adhyātma)? What is action (karma), O Supreme Person, What is described as pertaining to the underlying principle of being (adhibhūta)? And what is referred to as the underlying principle of destiny or divinity (adhidaiva)?"

अधियज्ञः कथं कोऽत्र देहेऽस्मिन् मधुसूदन। प्रयाणकाले च कथं ज्ञेयोऽसि नियतात्मभिः ॥२॥

O Madhusūdana, how is the principle of sacrifice (adhiyajña) present in this body, and where? And how are (You) to be known at the time of departure by those of a controlled mind?

श्रीभगवानुवाच, अक्षरं ब्रह्म परमं स्वभावोऽध्यात्ममुच्यते। भूतभावोद्भवकरो विसर्गः कर्मसञ्ज्ञितः ॥३॥

The Blessed Lord said: "The imperishable (akṣara) is the Supreme Brahman. One's essential nature (svabhāva) is called 'adhyātma', pertaining to self. The offering (visarga), which causes the origin of the existence of beings, is known as action (karma).

Gīta Bhāshya 8.01, 02, 03

'paramam akṣaraṁ' - The Supreme Brahman, the ultimate imperishable. 'adhyātma' - that which pertains to the 'ātman'. 'svabhāva = sva + bhava'; sva - excludes the concept of the Lord (Īśvara); bhāva - is that which exists always in one way only, consistently. svabhāva - the innate nature of the living being, called one's own. bhūtabhavodbhavakaro - the special act of arising of the universe by the Lord that includes living beings (bhūta) and the insentient (bhāvā). 'visarga' - the special arising of the universe.

॥ हरिः ॐ ॥

"Lord Hari, the remover of sins and protector is the ultimate reality (Om)."

मरणकालकर्तव्यगत्यादि अस्मिन् अध्याये उपदिशति। परमम् अक्षरं परं ब्रह्म। वेदादिशङ्काव्यावृत्त्यर्थम् एतत्। आत्मनि अधि यत् तत् अध्यात्मम्। 'आत्माधिकारे' यत् तत् इति वा। तथाहि जैवः स्वभावः। स्वाख्यो भावः इति व्युत्पत्त्या जीवो वा स्वभावः। सर्वदा अस्त्येव एकप्रकारेण इति भावः। अन्तःकरणादि व्यावृत्त्यर्थः भावशब्दः। न हि एकप्रकारेण स्थितिः अन्तःकरणादेः। विकारित्वात्। स्वशब्दः ईश्वरव्यावृत्त्यर्थः।

In this chapter, the duties, movements, and other considerations at the time of death are taught. The Supreme Brahman is the ultimate imperishable reality, the 'paramam akṣaraṁ', qualified by the adjective 'paramam'. It is reiterated to resolve doubts concerning the Vedas and others (which are lesser imperishables). That which pertains to the 'ātman', i.e. essence is termed "adhyātma". Alternatively, it can also mean the subject dwelled into in the 'ātma-adhikāra' ancient text. The word 'svabhāva' is etymologically derived as "the nature called one's own". Thus, it always refers to the innate nature of individual living being. The word 'bhāva' is that which exists always in one way only, consistently. Thus, the term "bhāva" excludes the internal organs (such as mind and senses) and others because their state is not stable in one manner and are subjected to distortion. The word "sva" (one’s own) excludes the concept of the Lord (Īśvara).

भूतानां जीवानां। भावानां जडपदार्थानां च उद्भवकरेश्वरक्रिया विसर्गः। विशेषेण सर्जनं विसर्ग इत्यर्थः ॥ १-३ ॥

(In the word 'bhūtabhāvodbhavakaro',) the word 'bhūta' refers to living beings (jīva).The word bhāva refers to insentient, inanimate objects. The act of arising (udbhavakara) caused by the Lord (īśvarakriyā) is referred to as 'visarga'. The adjective 'vi' in 'visarga' refers to the special universe (sarga).