vedānāṃ pauruṣeyatve siddhe siddhaṃ na sādhanam / ajñātasyopadeśo 'sti tathyo yādṛcchiko naraḥ //
When it has been established that the Vedas are of human origin, [our] proof does not establish what is [already] established, [and] random teaching by a person of what is unknown cannot be true.