法華論疏 2.431

2.431

經中稱一大事因緣，論明因緣是所以，所以即是義。今依此義故出現於世，故言依何等義。又依何等義者，以依開示悟入等四義，故云依何等義。又對上三乘有語無義、一乘有語有義，故云依何等義。

The sūtra speaks of "one great cause and condition"; the treatise clarifies that cause and condition is the reason, and the reason is the meaning. Now, it is by relying on this meaning that [the Buddhas] appear in the world; hence it says "what meaning it relies on." Furthermore, "what meaning it relies on" is stated because it relies on the four meanings of opening, revealing, awakening, and entering. Furthermore, by contrast with the above three vehicles having words but no reality while the One Vehicle has words and has reality, it says "what meaning it relies on."