妙法蓮華經玄贊 10.46

10.46

釋名者，依法修行可為軌範，故名法師。唯能行者，非所行法。此品明法師之功德，故名法師功德品。

As for explaining the title: practicing in accordance with the Dharma can serve as a model, hence one is called a “Dharma master.” This refers only to the capable practitioner, not the Dharma that is practiced. Because this chapter clarifies the merits of the Dharma master, it is called the “Chapter on the Merits of the Dharma Master.”