成唯識論述記 3.631

3.631

述曰：外難云：如一種子因於現在有作用時，後果未生，果法未來既體是無，不可定其所生之果。此說因者是誰之因，無果可屬因定能生彼故。問果亦爾，現為因即無果，現為果即無因，因果既無，斷、常誰離。初但難斷，今亦難常。

The Commentary states: The external challenge says: When a single seed, as cause, has activity in the present, the subsequent fruit has not yet arisen. Since the future fruit-dharma is non-existent in substance, its produced fruit cannot be determined. When you speak of a cause, whose cause is it? There is no fruit to which it can belong, [such that] the cause definitively can produce it. Questioning the fruit is also like this: being a cause in the present means there is no fruit; being a fruit in the present means there is no cause. Since cause and effect are non-existent, who is free from discontinuity and permanence? Initially they only challenged discontinuity; now they also challenge permanence.