大般涅槃經疏 29.6

29.6

「作是觀時」下，第三能斷善根，又為二：初明斷善、次料簡利鈍，悉如文。問：闡提昔有智慧習因，應有習果，何以斷善？答：但有世智，無出世智。以世智慧斷出世善，亦能斷於清升善根。世間此例其實不少。昔徐僕射理人甚善，為上虞，令犯事。不閑答問，如天柱瑜極解深義，不曉世語。此上智人闇於世事。而是闡提雖有世智，何必能知出世之法（云云）。

From "When making this contemplation..." downward is, third, being able to sever the roots of goodness, which is also in two parts: first, explaining the severing of the good; next, examining sharp and dull [faculties], all as in the text. Question: An icchantika previously possessed the causal practice of wisdom, and should have the habitual fruit; why does he sever the good? Answer: He possesses only worldly wisdom, and lacks supramundane wisdom. Using worldly wisdom to sever supramundane good, he is also able to sever pure and ascending roots of goodness. In the mundane world, such cases are in fact not rare. Formerly, Vice Director Xu governed the people very well, but when he served as the magistrate of Shangyu, he committed an offense. He was unversed in answering questions; just as Tianzhu Yu thoroughly understood deep principles yet was unacquainted with worldly vernacular. These people of superior intelligence were obscure regarding mundane affairs. And this icchantika, although possessing worldly wisdom, how could he necessarily know the supramundane Dharma? (And so forth).