四分律比丘含注戒本 2.235

2.235

佛在舍衛。六群比丘與六群尼人間遊行，居士譏嫌，比丘舉過，佛便訶制。

The Buddha was in Śrāvastī. The group of six bhikṣus journeyed among human settlements together with the group of six bhikṣuṇīs. Householders criticized and censured them. The bhikṣus brought up this fault, and the Buddha rebuked [them] and instituted the rule.