四分律比丘含注戒本 2.455

2.455

The Buddha was among the Śākyas. At that time, Mahānāman invited the saṃgha to provide them with medicine. Because the group of six [bhikṣus] held a grudge, they asked for hard-to-find medicines; he sought to buy them for them, whereupon they scolded and reviled him, and he ceased [giving] medicine to the saṃgha. Bhikṣus brought up the transgression, and the Buddha formulated the precept on account of this.