妙法蓮華經玄義 8.140

8.140

此門正意通大，傍通於小，譬如王國有通門別門，別門通朝士，通門通朝市，不可以民庶登踐，謂為民門。摩訶衍通門亦如是，正通實相，傍通真諦，故三乘灰斷，兼由此門，不可以兼通偏真，而名小乘門也。

The primary intent of this gate is to provide passage to the great, while collaterally providing passage to the small. For example, a royal realm has public gates and special gates; the special gates provide passage to court officials, while the public gates provide passage to both the court and the marketplace; one cannot say that because commoners tread through it, it is a gate of the commoners. The shared gate of the Mahāyāna is also like this: primarily it provides passage to the true mark, and collaterally it provides passage to the truth of emptiness; therefore the three vehicles' turning to ashes and extinction also occurs by way of this gate; one cannot, because it collaterally provides passage to the biased truth, call it a Hīnayāna gate.