Vālodaka Jātaka (No.183)
Once Brahmadatta, king of Bārāṇasī, went with a large army to quell a frontier rebellion, and, on his return, ordered that his horses be given some grape juice to drink. The horses drank and stood quietly in their stalls. There was a heap of leavings empty of all goodness, and the king ordered that these be kneaded with water, strained, and given to the donkeys who carried the horses’ provender. The donkeys drank it, and galloped about braying loudly. The king asked his courtier (the Bodhisatta) the reason for this, and he answered that the lowborn lack self control.
The story was told in reference to some boys, attendants of devotees, at Sāvatthi. The devotees themselves were calm and collected, but the boys would eat and then scamper about the banks of the Aciravatī, making a great uproar. They are identified with the donkeys (J.ii.95 f).
According to the Dhammapada Commentary (DhA.ii.154 f ) the story was related after the monks returned to Sāvatthi from Verañjā. Their attendants had been quiet in Verañjā, where there was little to eat, but in Sāvatthi they ate the remnants of the monks’ food and made a great noise.