Nyayasutra 84.3

84.3

manaḥsannikarṣānapekṣasya cendriyārthasannikarṣasya jñānakāraṇatve yugapad utpadyeran buddhaya iti manaḥsannikarṣo 'pi kāraṇam/ tad idaṃ sūtraṃ purastāt kṛtabhāṣyam/

And if contact of the sense organ and the object independent of contact with the mind were the cause of knowledge, cognitions would arise simultaneously; therefore contact with the mind is also a cause. This sūtra has already been commented upon previously.