tatra prayogaḥ yadapratibaddhasāmarthyaṃ yasmin kartavye, tat karotyeva, yathāntyā kāraṇasāmagrī, apratibaddhasāmarthyaṃ cākartṛkaṃ vākyaṃ jñānajanane sarvakālam iti svabhāvahetuḥ /
The argument here [is]: Whatever has unobstructed capacity for producing something must produce it, like the final aggregate of causes; and the authorless sentence has unobstructed capacity for generating cognition at all times - this is a svabhāvahetu [reason based on essential nature].