Charak Samhita
प्राणापानौ निमेषाद्या जीवनं मनसो गतिः। इन्द्रियान्तरसञ्चारः प्रेरणं धारणं च यत् ॥७०॥
In response to the question on the signs and symptoms of a soul in the living body, as well as the proofs of existence of the soul in living animates, Lord Atreya mentions the following as proof:
english translation
prANApAnau nimeSAdyA jIvanaM manaso gatiH। indriyAntarasaJcAraH preraNaM dhAraNaM ca yat ॥70॥
hk transliteration by Sanscript