妙法蓮華經玄義 10.126

10.126

次約四法論開合者，即是四教。約圓開別，約別開通，次開三藏，如是次第，會來合圓（云云）。又四法論開合者，約四門。本是圓四門，眾生不解，開出別四門，乃至通、三藏四門，利者得傳傳入，鈍者五味調入。

Next, discussing opening and merging in terms of four dharmas: this refers to the four teachings. In terms of the perfect, one opens the distinctive; in terms of the distinctive, one opens the shared; next, one opens the tripiṭaka. In this sequence, they converge and merge into the perfect (and so forth). Furthermore, discussing opening and merging in four dharmas is in terms of the four gates: originally they are the four gates of the perfect; because sentient beings do not understand, one opens the four gates of the distinctive, and even the four gates of the shared and the tripiṭaka. The sharp enter successively; the dull are seasoned and enter through the five flavors.