4.31
यज्ञशिष्टामृतभुजो यान्ति ब्रह्म सनातनम् | नायं लोकोऽस्त्ययज्ञस्य कुतोऽन्यः कुरुसत्तम ||३१||
yajña-śhiṣhṭāmṛta-bhujo yānti brahma sanātanam nāyaṁ loko'sty ayajñasya kuto'nyaḥ kuru-sattama
Translation
O best of the Kuru dynasty, without sacrifice one cannot live happily on this planet or in this life. What then of the next?
Interpretation
Those who eat the nectar left over from yajna (the prasad of spiritual practice) attain eternal Brahman. Without yajna — without the spirit of offering and participation in the cosmic exchange — one cannot be happy even in this world, let alone in the next. The principle of reciprocity and giving is built into the fabric of existence.