俱舍論疏 19.229

19.229

論「然彼所問至如何不名記」，答也。解云：第四記詳諸經、論，或記言不應記，亦是答第四。或全不答，亦是記第四問。今此中云「記言不可記」也。

Regarding the treatise passage from "However, what he asked" to "how could it not be called an answer?": this is the reply. The explanation is: Examining the fourth answer throughout the sūtras and treatises, answering by saying 'it should not be answered' is also answering the fourth. Or not answering at all is also answering the fourth question. Here it says, "answering by saying it is unaccountable."