妙法蓮華經玄義 2.58

2.58

今以譬解。譬如官有三航及以私船，從於此岸，度人彼岸。乳教如大中兩航，共度人彼岸。酪教如私船，度人中洲。生蘇如四種：小航與私船，度人於中洲：兩航度人於彼岸。熟蘇如三航：一航中洲，二航彼岸。醍醐如大航，度人彼岸。三航同是官物，故俱稱為滿。私船非官物，是故言半。官物之中，二航小，所容蓋寡；大航壯麗，容載倍多，獨稱為妙。智者以譬喻得解，其譬義如是（云云）。

Now I explain it with a metaphor. It is like the government possessing three large ferries along with private boats, ferrying people from this shore to the other shore. The milk teaching is like the large and medium ferries together carrying people to the other shore. The cream teaching is like a private boat ferrying people to an islet in the middle. The raw curds are like four kinds: the small ferry and the private boat ferry people to the islet in the middle, while two ferries carry people to the other shore. The cooked curds are like three ferries: one ferry to the islet in the middle, and two ferries to the other shore. Clarified butter is like the large ferry carrying people to the other shore. Because the three ferries are all alike government property, they are all called "full." The private boat is not government property, and therefore is called "half." Among the government vessels, two ferries are small and accommodate few; the large ferry is magnificent and carries many times more, and it alone is called subtle. The wise attain understanding through metaphors; the meaning of the metaphor is like this (and so forth).