涅槃經遊意 1.103

1.103

第二、肇師翻之以「滅度」，秦言「無為」，亦言「滅度」。以虛無寂漠，妙絕有為，名曰無為；以其大患永滅，超度四流，故云滅度。

Second, Master Zhao translated it as “extinction and crossing over” (miedu); in the language of Qin it is “unconditioned” (wuwei), and also called “extinction and crossing over.” Because it is empty, nothingness, tranquil, and silent, subtly transcending the conditioned, it is named unconditioned; because its great afflictions are eternally extinguished and it transcends the four currents, it is called extinction and crossing over.