Now, Krishna brings out the distinction among sacrifices performed in three modes of nature.

A sacrifice (yajño) that is (ya) performed (ijyate) by those who seek no fruits (aphalākāṅkṣibhir), according to the directions of scripture (vidhi-diṣṭo), as a matter of duty (yaṣṭavyam eveti), with the mind in full concentration (manaḥ samādhāya), is of the quality of goodness (sa sāttvikaḥ). (BG 17.11)

But (tu), a sacrifice (yajñaṁ) that is (yat) performed (ijyate) seeking (abhisandhāya) the fruit (phalaṁ) and also (api caiva) for the sake of deceit (dambhārtham), we should know that (taṁ viddhi) to be in the mode of passion (rājasam). (BG 17.12)

A sacrifice (yajñaṁ) performed without following any rules and regulations (vidhi-hīnam), without sharing of food (asṛṣṭānnaṁ), without chanting of mantra (mantra-hīnam), without offering gifts (adakṣiṇam), and without faith (śraddhā-virahitaṁ) is to be considered (paricakṣate) in the mode of darkness (tāmasaṁ). (BG 17.13)

In summary, a sacrifice in the mode of goodness and that in the mode of darkness are poles apart – the former is performed selflessly according to the directions of scriptures while the latter is bereft of any formal directions. A sacrifice in the mode of passion is characterized by utter selfishness.