翻譯名義集 5.120

5.120

【一門】《法華》云：「是舍唯有一門，而復狹小。」天台釋曰：別者，一謂一理，一道清淨。門謂正教，通於所通。小謂不容斷常七方便等。教理寬博，則非狹小；眾生不能以此理教自通，將談無機，故言狹小耳。通者，理純無雜故言一，即理能通故言門，微妙難知故言狹小。教者，十方諦求，更無餘乘，唯一佛乘故言一，此教能通故言門。

[One Gate]
The Lotus Sūtra says: 'This house has only one gate, and furthermore it is narrow and small.' Tiantai explains: Specifically, 'one' refers to the one principle, the one path of purity. 'Gate' refers to the correct teaching, leading through to that which is reached. 'Small' means not admitting the seven provisional expedients of eternalism, annihilationism, and so forth. If the teaching and principle are broad and vast, then it is not narrow and small; but because sentient beings cannot use this principle and teaching to reach through on their own, when speaking of those lacking capacity, it is therefore called narrow and small. Generally, because the principle is pure and unmixed, it is called 'one'; because the principle itself can lead through, it is called 'gate'; because it is subtle, wondrous, and difficult to know, it is called 'narrow and small'. In terms of the teaching: seeking throughout the ten directions, there are no other vehicles, only the One Buddha Vehicle, hence it is called 'one'; because this teaching can lead through, it is called 'gate'.