妙法蓮華經玄義 5.97

5.97

若有行人，歷諸教四譬五味過已，方得入圓教醍醐中殺人者，此是破三顯一，相形待為妙。若置毒乳中，味味悉殺人者，此是開權顯實，於一切法中即見中道。故文云：「汝等所行，是菩薩道。」不須更改途易轍而求真實，即麁見妙，故以置毒為喻。

If there is a practitioner who, only after traversing all teachings, the four parables, and the five flavors, finally enters the perfect teaching to be killed in ghee, this is destroying the three and revealing the one, being wonderful by mutual contrast. If placing poison into milk kills at every single flavor, this is opening the provisional and revealing the real, seeing the middle path immediately within all phenomena. Hence the text says: "What you are practicing is the bodhisattva path." There is no need to change roads or alter tracks to seek the real: the crude is immediately seen as wonderful. Therefore, the placing of poison is used as an analogy.