yadyetayor dhiyoḥ samyaktvaṃ gṛhītaṃ bhavettadābhyāṃ mithyātvaṃ gṛhyeta tathā ca samyaktvagrahaṇāya pramāṇāntarāpekṣāyāmanavasthā syād ityata āha utpattyavastham ityādi
If the correctness of these two cognitions were to be grasped, then falsity would be grasped through these two [cognitions], and thus due to requiring another means of valid cognition for grasping [their] correctness, there would be infinite regress - therefore he says "at the time of arising" etc.