華嚴經探玄記 1.36

1.36

Third, Vinaya Master Guangtong of the Later Wei, inheriting the tradition of Tripiṭaka Master Buddhabhadra, established three kinds of teachings: gradual, sudden, and perfect. Master Guang's meaning explained: First, for those whose faculties are not yet mature, first expounding impermanence and later expounding permanence, first emptiness and later non-emptiness, and so forth; such gradual progression is named the gradual teaching. Second, for those whose faculties are mature, completely expounding all Buddha-dharmas within a single doctrinal gate—meaning permanence and impermanence, emptiness and non-emptiness are all fully expounded without any dependence on gradual progression—hence named the sudden. Third, for those of superior attainment who have stepped into the Buddha realm, expounding the Tathāgata's unimpeded liberation, ultimate fruition virtues, and the perfectly culminating, esoteric, autonomous doctrinal gate, hence named the perfect. Thus, this sūtra is subsumed under the perfect and sudden. Later, Zuntong and other disciples of Guangtong all maintained and followed this, agreeing with this view.