大般涅槃經集解 34.14

34.14

案僧亮曰：轉法輪者，謂所說之法，令聽悟解為轉也，解以摧惑為輪也。若佛有說，則是有為有盡，何名涅槃？今無說而物聞、不滅而人自滅，故言不涅槃也。僧宗曰：疑有三意，此釋第一意也。

Sengliang comments: 'Turning the Dharma wheel' means that the Dharma taught causes listeners to awaken and understand, which is 'turning'; understanding shatters delusion, which is the 'wheel.' If the Buddha had speech, it would be saṃskṛta and exhaustible—how could it be called nirvāṇa? Now, without speech, beings hear; without extinguishing, people extinguish by themselves; therefore it is said that he does not enter nirvāṇa.
Sengzong says: The doubt had three points; this explains the first point.