俱舍論疏 15.13

15.13

論「支不定者至名律儀支故」，釋支不定。比丘、比丘尼具有七支，餘戒唯有身三、語一，謂五戒、八戒、十戒不同，四根本業道名律儀支故。

On the Śāstra's: "That the branches are variable... are called the branches of discipline", this explains that the branches are variable. Monks and nuns possess all seven branches; the remaining precepts possess only the three of body and one of speech—meaning that the five precepts, eight precepts, and ten precepts differ—because the four maula-karmapathas are called the branches of discipline.