四分律比丘含注戒本 3.13

3.13

The Buddha was in Śrāvastī. A great number of bhikṣus, together with the group-of-six, were eating at a layperson's house. At that time, the group-of-six bhikṣuṇīs asked for soup and rice, and out of order gave it to the group-of-six bhikṣus, saying: "Give soup to this one; give rice to this one." The bhikṣus reported the fault and informed the Buddha, who thereupon rebuked [them] and formulated the precept.