The Śūraṅgama Sūtra, Fascicle Three: The Nose Faculty as the Inherent Wonderful True Suchness Nature of the Tathāgatagarbha

Original text:阿难。譬如有人。急畜其鼻。畜久成劳。则于鼻中。闻有冷触。因触分别。通塞虚实。如是乃至。诸香臭气。兼鼻与劳。同是菩提。瞪发劳相。因于通塞。二种妄尘。发闻居中。吸此尘象。名嗅闻性。此闻离彼。通基二尘。毕竟无体。

Explanation: Ānanda, for example, if someone rapidly twitches their own nose, after twitching for a long time the nose will develop a mark of heaviness (dauṣṭhulya-lakṣaṇa) of contact, and within the nose one will feel a cool sensation. Because the nose contacts the mark of coldness, one will know whether the nose is open or blocked, empty or solid. Thus, even when the nose faculty contacts all kinds of fragrant and foul odors, the nose knows there is a sensation of contact. The nose faculty together with these marks of heaviness of contact are all marks of heaviness of contact generated forth from the bodhi mind. Because of knowing the illusory sense-objects of openness and blockage, the smelling nature arises within; the smelling nature absorbs these sense-object appearances and manifests various odor sense-objects — this is called the smelling nature. This smelling nature, apart from the two sense-objects of openness and blockage, ultimately has no self-nature of its own.

Original text:当知是闻。非通塞来。非于根出。不于空生。何以故。若从通来。塞则闻灭。云何知塞。如因塞有。通则无闻。云何发明。香臭等触。若从根生。必无通塞。如是闻机。本无自性。若从空出。是闻自当。回嗅汝鼻。空自有闻。何关汝入。是故当知。鼻入虚妄。本非因缘。非自然性。

Explanation: Ānanda, you should know that this smelling nature does not come from openness and blockage, does not emerge from the nose faculty, and is not produced from empty space. Why is this said? If the smelling nature came from openness, then when there is blockage the smelling nature would vanish — how could one then know that the nose is blocked? If the smelling nature arose from blockage, then when there is openness the smelling nature would vanish — how could one then discern the contact of fragrant and foul odors?

If the smelling nature emerged from the nose faculty, it would follow the attributes of the nose faculty: there would be neither the sense-objects of openness nor of blockage, and it would not know openness and blockage — what self-nature would such a smelling nature have? If the smelling nature came from empty space, then this smelling nature should itself turn around and smell your nose; empty space would have its own smelling nature — what would that have to do with your nose entrance? Therefore you should know that the smelling nature is illusory; it is fundamentally not a nature of causes and conditions, nor a nature of naturalness, but rather the nature of the tathāgatagarbha.