四分律行事鈔資持記 3.34

3.34

多少中，初科。《四分》止十九條，中品之極；《十誦》止十五條，中品之初；皆略上品，故並云若過也。然文非顯了，故引《多論》，具列大衣三位九品。《業疏》云：所以極齊二十五條者，欲為二十五有作福田故。

Regarding more or less, in the first section: The Dharmaguptaka-vinaya stops at nineteen strips, which is the limit of the middle grade; the Daśādhyāya-vinaya stops at fifteen strips, which is the beginning of the middle grade; both omit the upper grade, hence both say 'if exceeding'. However, since the text is not obvious, it cites the Sarvāstivāda Vinaya Vibhāṣā to list fully the three ranks and nine grades of the great robe. The Karma Commentary states: 'The reason it culminates strictly at twenty-five strips is that it intends to serve as a field of merit for the twenty-five realms of existence.'