妙法蓮華經玄義 7.50

7.50

五、約實權明本迹者，實者，最初久遠實得法、應二身，皆名為本；中間數數唱生、唱滅，種種權施法、應二身，故名為迹。非初得法、應之本，則無中間法、應之迹。由迹顯本，本迹雖殊，不思議一也。文云：「是我方便，諸佛亦然。」

Fifth, clarifying the original source and the traces in terms of the real and the provisional: as for the real, originally and long ago truly attaining both the dharma and response bodies is named the original source; intermediate times of repeatedly declaring birth and declaring extinction, provisionally applying both the dharma and response bodies in various ways, are therefore named traces. Were it not for the original source of first attaining the dharma and response [bodies], there would be no intermediate traces of the dharma and response [bodies]. Through the traces the original source is revealed; although original source and traces are distinct, they are an inconceivable unity. The text says: "These are my expedient means; so too with the other buddhas."