仁王護國般若波羅蜜多經疏 1.37

1.37

Regarding explaining the chapter name: the word "preface" (xu) means cause and origin, referring to the causes and reasons for the arising of the preaching of prajñā. The word "chapter" (pin) means category, where texts and meanings gather together into distinct divisions. The word "ordinal" (di) is the location of sequence. The word "one" (yi) is the beginning of numbers. This sūtra as a whole has eight chapters in all; this chapter is at the beginning, and therefore it is called the first.