妙法蓮華經玄義 10.122

10.122

六、增數明教者，先、約迹，次、約本。夫教本逗機，機既不一，教迹眾多，何但半滿五時，當知無量種教，今且增一至八。

Sixth, clarifying the teachings through increasing numbers: first regarding the traces, next regarding the original source. Teachings fundamentally adapt to capacities; since capacities are not unified, the traces of teaching are manifold—how could they merely be the half and full words of the five periods? One should know that there are immeasurable kinds of teachings; now we will increase from one to eight.