大乘玄論 3.13

3.13

料簡第十。然料簡中應論得失義。若本來清淨，何因緣故失？本既不失，今云何失？若後失者，先亦應失；先既清淨，後亦應淨。答此義者，如第九卷說，解純陀疑差別無差別義。若廣辨者，備舉《涅槃》一部來解釋，猶亦不可盡。此義不可卒了，且待後問也。

Tenth, critical evaluation. In the critical evaluation, one should discuss the meaning of gaining and losing. If it is originally pure, by what causes and conditions is it lost? Since originally it was not lost, how is it lost now? If it is lost later, it should also have been lost previously; since it was previously pure, it should also be pure later. The answer to this meaning is as explained in the ninth roll, resolving Cunda's doubt on the meaning of distinction and non-distinction. If extensively explained, even completely adducing the entire Nirvāṇa[sūtra] to explain it would still not exhaust it. This meaning cannot be finished in haste; let it wait for a later question.