妙法蓮華經玄義 10.38

10.38

又難常宗指於《涅槃》，《涅槃》之經何但明常，亦明非常、非無常，能常、能無常雙用，具足八術，云何單取常用為宗？何不取無常用為宗？單輪隻翼，不能飛運（云云）。

Furthermore, I critique the eternal tenet referring to the Nirvāṇa: how could the Nirvāṇa-sūtra only clarify the eternal? It also clarifies neither eternal nor impermanent, deploying both the ability to be eternal and the ability to be impermanent, complete with the eight methods. Why take the eternal alone as the tenet? Why not take the impermanent as the tenet? A single wheel or a single wing cannot travel or fly (and so forth).