四分律比丘含注戒本 3.474

3.474

此佛「略教」，即是「略」之正宗也。時接利根，無再犯者。後因重過，佛止不說，即以廣、略二教付弟子說也。

This Buddha's "abbreviated teaching" is the core text of the "abbreviated [precepts]." At that time, it guided those of sharp faculties, and none committed repeated infractions. Later, due to grave transgressions, the Buddha ceased speaking [it himself] and entrusted both the expanded and abbreviated teachings to his disciples to recite.