यज्ञशिष्टाशिनः सन्तो मुच्यन्ते सर्वकिल्बिषैः | भुञ्जते ते त्वघं पापा ये पचन्त्यात्मकारणात् ||३-१३||
yajñaśiṣṭāśinaḥ santo mucyante sarvakilbiṣaiḥ . bhuñjate te tvaghaṃ pāpā ye pacantyātmakāraṇāt ||3-13||
Chapter 3 · Verse 13
Karma Yoga
कर्मयोग
In plain words
You are urged to cook and eat with a sense of sacred sharing rather than selfish desire. When you prepare food only for yourself, you accumulate negative karma, or spiritual debt. But when you offer your food first to others and the divine, you are purified and freed from all selfish attachments.
Translation
3.13 Pious men who eat the remnants of sacrifices are freed from all sins. But the sinful ones who cook only for their own sake earn only sin.
Meaning
Those who after performing the five great sacrifices eat the remnants of the food are freed from all the sins committed by these five agents of insect slaughter viz. (1) the pestle and mortar (2) the grinding stone (3) the fireplace (4) the place where the waterpot is kept and (5) the broom. These are the five places where injury to life is daily committed. The sins are washed away by the performance of the five MahaYajnas or great sacrifices which every Dvija(twicorn or the people belonging to the first three castes in Hindu society especially the Brahmin) ought to perform1. DevaYajna Offering sacrifices to the gods which will satisfy them 2. BrahmaYajna or RishiYajna Teaching and reciting the scriptures which will satisfy Brahman and the Rishis 3. PitriYajna Offering libations of water to ones ancestors which will satisfy the manes 4. NriYajna The feeding of the hungry and the guests and 5. BhutaYajna The feeding of the subhuman species such as animals birds etc.
Word by word
यज्ञशिष्टाशिनः who eat the remnants of the sacrifice सन्तः the righteous मुच्यन्ते are freed सर्वकिल्बिषैः from all sins भुञ्जते eat ते those तु indeed अघम् sin पापाः sinful ones ये who पचन्ति cook आत्मकारणात् for their own sake.