Chāndogya Upaniṣad 2.12.2

2.12.2

sa ya evam etad rathaṃtaram agnau protaṃ veda \
brahmavarcasy: annādo bhavati \
sarvam āyur eti \
jyog jīvati \
mahān prajayā paśubhir bhavati \
mahān kīrtyā \
na pratyaṅṅ agnim ācāmen na niṣṭhīvet \
tad vratam \\212.2\

2. He who knows thus this Rathantara Sāman as woven upon fire becomes an eater of food, eminent in sacred knowledge, reaches a full length of life, lives long, becomes great in offspring and in cattle, great in fame. One should not take a sip and spit toward fire. That is his rule.