Krishna now explains how when one’s knowledge and action transcendentally combine, the action becomes a sacrifice (yajña).

For one who is free from attachment (gata-saṅgasya) and liberated (muktasya) with mind fixed in knowledge (jñānāvasthita-cetasaḥ), any action (karma) being performed in the spirit of sacrifice (yajñāyācarataḥ) is completely (samagraṁ) dissolved (pravilīyate) [in transcendence]. (BG 4.23) Anything done with transcendental consciousness (for the sake of Krishna) is called a sacrifice. In that stage, everything merges into transcendence as one experiences freedom from bondage in this world.

The contribution becomes brahman [spiritual] (brahmārpaṇaṁ), the offering [of butter] (havir) becomes brahman [spiritual] (brahma), being offered (hutam) into the fire [consuming agent] of (āgnau) brahman [spiritual] (brahma) by a brahman-realized soul (brahmaṇā) with total absorption of (samādhinā) action (karma) in transcendence (brahma). Brahman alone (brahmaiva) is meant to be attained (gantavyaṁ) by such a soul (tena). (BG 4.24)

In a traditional sacrifice (yajña), all the components of sacrifice, viz., the goal (gantavyaṁ), the offering (havi), the consuming agent (agni), contribution (arpaṇam), contributor (brahmaṇā hutam), and the process (karma) become spiritualized. Thus, in general, actions performed in transcendental knowledge and in the spirit of sacrifice become spiritual. When the mind is fully absorbed in transcendental consciousness, it is called samadhi.

Some (apare) yogīs (yoginaḥ) worship (paryupāsate) the demigods (daivam) alone (eva) through sacrifices (yajñaṁ), and some (apare) offer (upajuhvati) sacrifice (yajñaṁ) into the fire of (āgnāu) Brahman (brahma) by sacrifice alone (yajñenaiva). (BG 4.25)

There are two primary divisions of sacrifice: the sacrifice of material possessions (acknowledging and giving back to the cosmic managers or demigods) and the sacrifice of material designations (readiness to give up everything in a sincere pursuit of the Absolute Truth).

Some others (anye) offer (juhvati) senses such as hearing (śrotrādīnīndriyāṇy) into the fire of (āgniṣu) self-control (saṁyama), and some others (anya) offer (juhvati) the sense object (viṣayān) such as sound (śabdādīn) into the fire of (āgniṣu) the senses (indriya). (BG 4.26) And, some (cāpare), ignited by knowledge (jñāna-dīpite), offer (juhvati) the functions of all the senses (sarvāṇīndriya-karmāṇi), and the functions of the life energy (prāṇa-karmāṇi) into the yoga-fire (yogāgnau) of self-control (ātma-saṁyama). (BG 4.27)

There are sacrifices recommended according to one’s social and spiritual position. A Vedic student offers senses such as hearing into the self-control fire by acting according to a teacher’s instructions. Others offer sense objects such as sound into the fire of the senses by allowing the senses to be spiritualized by transcendental sound vibration. The Yogis sacrifice all sense and breath actions into the fire of yogic self-control ignited by knowledge. However, these categories of sacrifice by different types of performers only superficially demarcate the varieties of sacrifice.

And (tathā), some others (apare) offer (juhvati) the incoming breath (prāṇaṁ) into the outgoing breath (apāne), the outgoing breath (apānaṁ) into the incoming breath (prāṇe), and then stopping (ruddhvā) the flow of (gatī) the incoming and outgoing breaths (prāṇāpāna) take shelter in (parāyaṇāḥ) breath control (prāṇāyāma). Some (apare), controlling the eating process (niyatāhārāḥ), offer (juhvati) the incoming breath (prāṇān) into the incoming breath (prāṇeṣu). (BG 4.29)

In today’s day and age (the Age of Kali), the recommended sacrifice is saṅkīrtana-yajña. The tongue acts as ladle that pours the offering of the Holy Name into the fire of our heart. The result is the purification of our hearts.

Overall, a sacrifice involves progressively sacrificing one’s (i) material possessions (dravya-yajña), (ii) gross body (tapo-yajña), (iii) breath and mind (yoga-yajña), and (iv) intellect (svādhyāya-jñāna-yajñā) – moving from the gross to the subtle objects (BG 4.28). Thus everything restores to its innate spiritual potency by dedicating it for the pleasure of the Supreme Lord.