四分律比丘含注戒本 1.514

1.514

佛在舍衛國。時，跋難陀往無住處村，以生薑易食，食已持去。舍利弗後至乞食，檀越以跋難陀事徵之，慚愧無言。又共外道博衣，悔而不得。比丘舉過，佛因制戒。

The Buddha was in the country of Śrāvastī. At that time, Upananda went to an uninhabited village and traded fresh ginger for food; having eaten, he carried [the rest] away. Śāriputra later arrived to beg for food, and the dānapati questioned him about Upananda's deed; ashamed, he had no words to reply. Furthermore, [Upananda] traded robes with a non-Buddhist, regretted it, but could not get them back. Bhikṣus raised the fault, and the Buddha laid down the precept on that basis.