Śatapatha Brāhmaṇa ("of a hundred paths") 10.2.6.6

10.2.6.6

tadetadṛcābhyuktaṃ vibhaktāraṃ havāmahe vasościtrasya rādhasaḥ savitāraṃ nṛcakṣasamiti tadetatsarvamāyurdīrghamanantaṃ hi tadyadidamāhurdīrghaṃ ta āyurastu sarvamāyurihītyeṣa te loka etatte'stviti haivaitat

It is regarding this that it is said in the Rik (I, 22, 7; Vâg. S. XXX, 4), 'The distributer of wealth, the bright boon, we invoke, Savitri, the beholder of men.' And that is the full (measure of) life, for it is long, it is unending; and when people here say, 'May thy life be long! mayest thou reach the full (extent of) life!' it is as much as to say, 'May that, world, may that (immortal light) be thine!'