維摩經玄疏 4.122

4.122

二、通室內者，室內託疾興教，示於病行，同一切眾生之實病。眾生之疾，雖有多塗，論其正意，不出四種。今以四種之迹病行，同四種之實病，即是現病行之迹，為〈問疾品〉也。次下五品皆從此品出，若通〈問疾品〉，下五品皆自通也。

Second, applying to what is inside the room: inside the room he feigns illness to initiate the teaching, displaying the conduct of illness to match the real illness of all living beings. Although the illnesses of living beings have many varieties, when discussing their main import, they do not exceed four kinds. Now, using four kinds of trace conduct of illness to match the four kinds of real illness is precisely manifesting the trace of the conduct of illness, which constitutes the "Chapter on Inquiring after Illness." The next five chapters all issue from this chapter; if one applies it to the "Chapter on Inquiring after Illness," the five chapters below naturally apply as well.