Which Consciousness Can Perfectly and Clearly Know Without Depending on Mental Thoughts?

The Śūraṅgama Sūtra contains a passage: 如此会中摩诃迦叶，久灭意根，圆明了知不因心念。 Question: When it says Mahākāśyapa has long extinguished the manas, which consciousness does this refer to as extinguished? And what does it mean to extinguish?

Answer: A person with the superknowledge of knowing others' minds can perceive others' mental activity anytime and anywhere, as long as the other person has mental activity. If the other person is rather deep and reserved, without mental activity, or if the other person possesses meditative concentration and does not give rise to thoughts at will, then their mental activity cannot be perceived, and the superknowledge of knowing others' minds becomes useless. Which mind's activity does this "mental activity" refer to?

What the superknowledge of knowing others' minds cognizes is the mental activity of the mind consciousness, because the mental activity of the mind consciousness involves language and words or sounds—and sounds include the inner voice of the mind. In this way, the mental conduct of the mind consciousness takes on a discernible form and is easy to cognize. The mental activity of the manas, however, has no language, words, or sounds, and no obvious marks of conduct, so it is not easily cognized. To cognize the mental conduct of the manas, one must do so through bodily, verbal, and mental actions, cognizing it through the workings of the body faculty and the mind consciousness.

So when Mahākāśyapa has long extinguished the manas, what exactly has he extinguished, such that he can perfectly and clearly cognize without relying on mental activity? Certainly this "mental activity" refers to the mental activity of the mind consciousness. Mahākāśyapa's perfect and clear cognition does not operate through the knowing of the mind consciousness; rather, the manas knows directly, knowing the inner and outer realms of the six sense objects, directly substituting for the knowing of the six consciousnesses. Therefore, what Mahākāśyapa extinguished is the mind consciousness and its mental activity, not the manas. If the manas had been extinguished, Mahākāśyapa's five aggregates would no longer exist, and he would have entered nirvāṇa without remainder (anupadhiśeṣa-nirvāṇa).