The Compendium of Caraka 1.30.20

1.30.20

tatra cet praṣṭāraḥ syuḥ caturṇāmṛksāmayajuratharvavedānāṃ kaṃ vedamupadiśantyāyurvedavidaḥ kimāyuḥ kasmādāyurvedaḥ kimarthamāyurvedaḥ śāśvato 'aśāśvato vā kati kāni cāsyāṅgāni kaiścāyamadhyetavyaḥ kimarthaṃ ca iti //

If there should be questioners inquiring: 'Of the four Vedas—the Ṛgveda, Sāmaveda, Yajurveda, and Atharvaveda—which Veda do knowers of Āyurveda point to? What is lifespan? Why is it called Āyurveda? What is the purpose of Āyurveda? Is it eternal or non-eternal? How many and what are its limbs? And by whom should it be studied, and for what purpose?'