Shatapatha Brahmana 10.3.5.13

10.3.5.13

tṛptirevāsya gatiḥ tasmādyadānnasya tṛpyatyatha sa gata iva manyata ānanda evāsya vijñānamātmānandātmāno haiva sarve devāḥ sā haiṣaiva devānāmaddhāvidyā sa ha sa na manuṣyo ya evaṃviddevānāṃ haiva sa ekaḥ

Satiation (contentment), doubtless, is the successful issue thereof (to wit, of food, and the Yagus): hence when one is satiated by food he feels like one who has succeeded. And joy, the knowledge thereof (viz. of the essence, the mystic import), is its soul (self); and, assuredly, all the gods are of joyful soul; and this, the true knowledge, belongs to the gods alone,--and, indeed, whosoever knows this is not a man, but one of the gods.