四分律比丘含注戒本 3.62

3.62

The Buddha was in Śrāvastī. The group of six wore their robes untidily, and householders saw and criticized them: "They claim, 'We know the true Dharma,' but what true Dharma is there in this? They wear their robes untidily, no different from laymen." The bhikṣus reported the fault to the Buddha, and after contemplating the three periods of time, he laid down this precept.