prayogaḥ yan mithyātvahetudoṣasaṃsargarahitaṃ tadavitathajñānakāraṇaṃ, yathā timirādidoṣānupaplutaṃ cakṣuḥ, mithyātvaheturāgādidoṣasaṃsargarahitaścāpauruṣeyatvād veda iti svabhāvahetuḥ /
The logical application is: Whatever is free from connection with defects that cause falsity is a cause of true knowledge - like an eye not affected by [diseases] such as timira; and the Veda, being non-human in origin, is free from defects like attachment etc. which cause falsity - this is an argument based on essential nature.