法華論疏 3.115

3.115

以三為一令入大乘者，非是三外別更有一，以會三乘終歸一乘，如會三聚米成於一斗米也。一論大宗如是，故下文云「破二歸一」。又上文云「三乘同一乘者，同一法身故」。

"Taking the three as one to cause them to enter the Mahāyāna" does not mean there is another one existing apart from the three; it means integrating the triyāna to ultimately return to the ekayāna, just as gathering three heaps of rice forms one dou of rice. The treatise's grand theme is like this; hence the text below says: "breaking the two to return to the one." Furthermore, the text above says: "the three vehicles are the same as the one vehicle because they share the same dharmakāya."