Śatapatha Brāhmaṇa ("of a hundred paths") 10.4.4.3

10.4.4.3

sa sahasratame saṃvatsare sarvo'tyapavata sa yaḥ so'tyapavatāyameva sa vāyuryo'yam pavate'tha yaṃ tam pāpmānamatyapavatedaṃ tacarīraṃ ka u tasmai manuṣyo yaḥ sahasrasaṃvatsaramavarundhīta vidyayā ha vā evaṃvitsahasrasaṃvatsaramavarunddhe

In the one-thousandth year, he cleansed himself all through; and he that cleansed all through is this wind which here cleanses by blowing; and that evil which he cleansed all through is this body. But what is man that he could secure for himself a (life) of a thousand years? By knowledge, assuredly, he who knows secures for himself (the benefits of a performance) of a thousand years.