四分律比丘含注戒本 2.435

2.435

佛在舍衛。迦留陀夷與齋優婆私露地共坐，乞食比丘見嫌之，具向諸比丘說。以過白佛，因而制戒。

The Buddha was in Śrāvastī. Kālodayin sat together with an upāsikā observing the eight precepts in an open place. Bhikṣus begging for alms-food saw them and disapproved, recounting it in detail to the bhikṣus. They reported the transgression to the Buddha, who thereupon formulated the precept.