Shatapatha Brahmana 2.1.4.9

2.1.4.9

aharvai devāḥ | anapahatapāpmānaḥ pitaro na pāpmānamapahate martyāḥ pitaraḥ purā hāyuṣo mriyate yo 'nudite manthatyapahatapāpmāno devā apa pāpmānaṃ hate 'mṛtā devā nāmṛtatvasyāśāsti sarvamāyureti śrīrdevāḥ śriyaṃ gacati yaśo devā yaśo ha bhavati ya evaṃ vidvānudite manthati

The gods, assuredly, are the day. The fathers have not the evil dispelled from them (by the sun); (and accordingly) he (the sacrificer) does not dispel the evil (if he churns the fire before sunrise). The fathers are mortal; and verily he who churns the fire before the rising of the sun, dies before (he has attained his full measure of) life. The gods have the evil dispelled from them (by the sun): hence he (the sacrificer) dispels the evil (from himself, if he churn after sunrise). The gods are immortal; and--though there is for him no prospect of immortality--he attains (the full measure of life). The gods are bliss, and bliss he obtains; the gods are glorious, and glorious he will be, whosoever, knowing this, churns (the fire) after the rising of the sun.