諸經之首，有通序別序，如是我聞等之六成就，通諸經有之，曰通序，本經特殊之緣起曰別序。參照序條。
The two kinds of introductory phrase: (a) the ordinary opening phrase of a sutra— "Thus have I heard"; and (b) specific openings referring to the circumstances in which the sūtra was produced.
諸經開頭時，有通序和別序。如是我聞等是共通於諸經都有，叫通序，序說本經特殊的緣起，叫別序。