Bhagavad Gita · 4.30

अपरे नियताहाराः प्राणान्प्राणेषु जुह्वति।सर्वेऽप्येते यज्ञविदो यज्ञक्षपितकल्मषाः॥

apare niyatāhārāḥ prāṇān prāṇeṣhu juhvati sarve 'py ete yajña-vido yajña-kṣhapita-kalmaṣhāḥ

Others, regulating their food intake, offer the life-breaths into the life-breaths as sacrifice. All of these are knowers of sacrifice and their sins are cleansed through sacrifice.

— Bhagavad Gita 4.30

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)