Various kind of divine yajnas

 (Krishna creates a metaphoric picture of various kind of yajnas)

Krishna talks about various yajnas/ Hawanas (a ritual where various kinds of offerings are made to the fire) that lead towards the supreme union—the yoga. ‘Dravya-yajna(by offering various kinds of sacred liquids), ‘tapo-yajna(by observing various hardships), ‘yoga-yajna (by mastering various yoga-asanas), then there’s ‘vag-yajna (when words are offered to words), and when through the offering of knowledge union with the supreme spirit is attained. All these yajnas are extremely difficult to perform and observe but not for the ones who have won over their senses and have offered their souls to the supreme spirit. They are the only ones eligible to perform such yajnas.

Krishna also talks about various kinds of pranayams and that is also a kind of yajna.

Some perform Hathyoga by practicing hardships to win over their senses. and so like this these people who practice these yajnas get rid of their desires, anger, false knowledge, and ignorance and obtain oneness such that no thoughts can enter the mind space (mana) of such a being and thus he remains clear of jealousy and lust.

In this way those who drink the remaining nectar of knowledge obtained from these yajnas, naturally, obtain their union with the Brahm (the supreme spirit) and thus can be said to have attained the mantra- ‘ahambrahmasmi’-

Krishna also insists that though all these yajnas are mentioned in ancient Vedas, one may not go through lengths of description of these rituals but rather pay attention to the essence—and that is, these yajnas are obtained from karmas(actions) and by knowing this there’s no blemish on the soul through the karmas.

All kind of yajnas mentioned in the Vedas which are full of rituals and all, cannot compare to the ‘gnyana-yajna’ just like the glare of the Sun overshadows every other planetary presence.

Krishna now describes that which is called enlightened knowledge and asks Arjuna if he desire to attain such enlightened knowledge, then he should serve saints and sages who are the storehouse of such enlightened knowledge.

P.s.-- Serving the sages-- however as guided by Krishna thousands of years back when sages were real enlightened beings. Considering contemporary times, all kind of sages are present and one needs to be very mindful of illusory nature of our times.