Shatapatha Brahmana 13.2.1.6

13.2.1.6

īśvaro vā eṣaḥ parāṅ pradaghoryaḥ parācīrāhutirjuhoti naikaśatamatyeti yadekaśatamatīyādāyuṣā yajamānaṃ vyardhayedekaśataṃ juhoti śatāyurvai puruṣa ātmaikaśata āyuṣyevātmanpratitiṣṭhati vyuṣṭyai svāhā svargāya svāhetyuttame āhutī juhoti rātrirvai vyuṣṭirahaḥ svargo'horātre eva tatprīṇāti

But, verily, he who offers the oblations straight away, is liable to fall (pass) right away. He does not go beyond a hundred and one: were he to go beyond a hundred and one, he would deprive the Sacrificer of his vital power. He offers a hundred and one, for man has a life of a hundred (years), and his own self is the one hundred and first: he thus establishes himself in a self (or body), in vital power. With 'To the Dawn hail! to Heaven hail!' he offers the two last oblations; for the dawn is the night, and heaven (the realm of light) is the day: it is day and night he thus gratifies.