Śatapatha Brāhmaṇa ("of a hundred paths") 2.1.3.4

2.1.3.4

sa yatrodagāvartate | tarhyagnī ādadhītāpahatapāpmāno devā apa pāpmānaṃ hate 'mṛtā devā nāmṛtatvasyāśāsti sarvamāyureti yastarhyādhatte 'tha yatra dakṣiṇāvartate yastarhyādhatte 'napahatapāpmānaḥ pitaro na pāpmānamapahate martyāḥ pitaraḥ purā hāyuṣo mriyate yastarhyādhatte

When he (the sun) moves northwards, then one may set up his fires;--the gods have the evil dispelled from them (by the sun): he (the sacrificer) therefore dispels the evil from himself;--the gods are immortal: he therefore, though there is for him no prospect of immortality, attains the (full measure of) life, whosoever sets up his fires during that time. Whosoever, on the other hand, sets up his fires when (the sun) moves southwards, he does not dispel the evil from him,--since the fathers have not the evil dispelled from them (by the sun). The fathers are mortal: hence he dies before (he has attained the full measure of) life, whosoever sets up his fires during that time.