Sri Krishna explains the mental attitude of a saint when he comes in contact with the world and functions in it. The Lord is enumerating in these verses twelve different types of Yagnas, each one apparently meaning ritualism but in fact suggesting different patterns of life wherein by the necessary adjustments in the mind we can effectively change the entire reactions of the world upon us.
Deva Yagna – Some Yogis perform sacrifice to Devas alone: According to ritualism this means invoking the grace of a specific deity and offering oblations to it in the sacred fire for gaining its blessings. But here it means that the perfect masters (Yogis) when they move in the world do perceive objects but their understanding and experience of the perception is of such a nature that the world of objects was subservient to the five sense organs which are Devas. When this mental attitude is entertained by the seeker, he feels detached from the sense experience and is able to have a sense of inner equanimity. It is surrendering individual consciousness to Cosmic Consciousness.
Brahma Yagna – Offering the Self as a sacrifice by the Self in the fire of Brahman: The outer world by itself is incapable of giving us sorrow or joy; but it is our attitude towards the objects and situations of the outer world that brings us such feelings. The perfect masters understand that the sense organs are mere instruments of perception and tune them to sacrifice themselves in the knowledge of the Brahman. When an individual’s organs of perception and action are to function not for satisfying his selfish needs but for the sake of serving the society at large, then although he lives in the world of objects he will not have any attachment to them.
The limiting accessories such as body, mind and intellect which are super imposed on the Self through ignorance are subordinated and the identity of the individual soul with the Supreme Soul is realized. The offering of the Self in the Brahman is to know that the Self which is associated with the limiting adjuncts is identical with the unconditioned Supreme Brahman. This is called Brahma Yagna wherein the Self is divested of Its Upadhis or limiting adjuncts so that it is recognized as the Supreme Self or Brahman.
Brahman is described in the scriptures as Consciousness, Knowledge and Bliss and as the innermost Self of all. It is devoid of all limitations imposed by time, space and causality. The individual self is in reality Brahman, but appears as the individual through association with the body, mind, intelligence and senses. To know the conditioned self as one with the unconditioned Brahman is to sacrifice the self in the fire of Brahman. This sacrifice is performed by those who have renounced all action and are devoted to the Knowledge of Brahman.

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Apare, other; yoginah, yogis, ritualists; pari-upasate, undertake; yajnam, sacrifice; daivam, to gods; eva, alone. A sacrifice by which the gods are adored is daiva-yajna; they perform only that. This is the meaning.

Brahma-agnau, in the fire of Brahman: By the word brahman is meant That which is referred to in such sentences as, ‘Brahman is Truth, knowledge and infinite’ (Tai. 2.1), ‘Knowledge, Bliss, Brahman’ (Br. 3.9.28), ‘the Brahman that is immediate and direct-the self that is within all’ (Br.3.4.1), which is devoid of all worldly characteristiscs like hunger etc. and which is beyond all particular qualifications-as stated in, ‘Not this, not this’ (Br.4.4.22). That which is Brahman is the fire. [Brahman is called fire because, as reflected in wisdom, It burns away everything, i. e. ignorance, or because everything merges into It during dissolution (pralaya).] And it is spoken of as Brahmagni with a view to referring to It as that into which the offering is made.

In that fire of Brahman, apare, others, other knowers of Brahman; upa-juhvati, offer; yajnam, the Self, which is referred to by the word yajna (sacrifice), it, having, been presented as a synonym of the Self;-that Self, which is a sacrifice, which is reality is verily the supreme Brahman, which is associated with such limiting adjuncts as the intellect etc., which is associated with all the qualities of the limiting adjuncts superimposed on it, and which is the oblation, (they offer) yajnena, by the Self itself as described above. The offering (of the Self) in that (Brahman) is nothing but the realization of that Self which is assoicated with the limiting adjuncts to be the supreme Brahman which is free from adjuncts. The monks, steadfast in the realization of the identity of Brahman and the Self, make that offering. This is the meaning.

Beginning with, ‘The ladle is Brahman’ etc., this sacrifice characterized as full realization is being included among such sacrifices as daiva-yajna etc. with a view to eulogizing it in the verses beginning with, ‘O destroyer of enemies, jnana-yajna is greater than the sacrifices involving (sacrificial) materials’.