The Compendium of Caraka 4.6.28_10

4.6.28_10

yadi hyakāle mṛtyurna syānniyatakālapramāṇamāyuḥ sarvaṃ syāt; evaṃ gate hitāhitajñānamakāraṇaṃ syāt, pratyakṣānumānopadeśāścāpramāṇāni syurye pramāṇabhūtāḥ sarvatantreṣu, yairāyuṣyāṇyanāyuṣyāṇi copalabhyante/

For if there were no untimely death, all lifespan would have a fixed measure of time; this being the case, knowledge of the wholesome and unwholesome would be purposeless, and perception, inference, and authoritative instruction—which are authoritative means of knowledge in all treatises, by which wholesome and unwholesome factors for longevity are understood—would become invalid.