妙法蓮華經玄贊 3.149

3.149

贊曰：此釋也。論釋種種因緣者，謂三乘法，彼三乘法唯名字章句說，非有實義故，以彼實義不可說故。此中意說，我以方便說三乘法，此法唯有名字章句無別三體，隨宜說三，非二乘等思量能解，唯佛能知。此說前標智門難了，三乘實義即是真如，不可說故。下依何等，即佛智慧。

The Commentary says: This is the explanation. The treatise explains that "various causes and conditions" refers to the teachings of the three vehicles; those teachings of the three vehicles are expounded merely through names, words, and phrases, and are not possessed of real meaning, because that real meaning cannot be spoken. The meaning expounded here is: I, by means of expedient means, expounded the teachings of the three vehicles; these dharmas possess only names, words, and phrases, without three distinct substances; expounding three in accord with suitability is not something the two vehicles and others can understand through conceptual deliberation—only a buddha can know it. This refers to the previously stated gateway of wisdom being difficult to comprehend; because the real meaning of the three vehicles is precisely tathatā, it cannot be spoken. What it relies upon below is precisely the Buddha's wisdom.