涅槃經遊意 1.163

1.163

今難此義，若涅槃有本有始，亦應有曾有今；若有曾有今，則成三世；三世無常，常法無曾無今者。常法無本如，既有本有始，則應有曾今，便成三世無常。

Now I challenge this meaning: if nirvāṇa had an origin and a beginning, it should also have a past and a present; if it had a past and a present, it would constitute the three times; the three times are impermanent, whereas a permanent dharma has neither past nor present. A permanent dharma has no origin or beginning; since you maintain that it has an origin and a beginning, it must have a past and a present, and would thus constitute the impermanence of the three times.