tathā hi na tāvad vedasya prāmāṇyaṃ pratīyate yāvad apauruṣeyatā na sādhyata ity āśaṅkyāha aprāmāṇyetyādi
For the validity of the Veda cannot be recognized until its authorlessness is established - anticipating this objection, [the author] states [the verse] beginning with "aprāmāṇya."