Musnad Ahmad 1086:4

Yazid ibn Harun narrated to us, Muhammad ibn Ishaq narrated to us, from al-Zuhri, from Haram ibn Sa'idah ibn Muhayyisah ibn Mas'ud, who said: He had a cupper slave, who was called Abu Taybah, who earned much earnings. When the Messenger of Allah, peace and blessings of Allah be upon him, forbade the earnings of the cupper, the Messenger of Allah, peace and blessings of Allah be upon him, was asked to lower the price for him, but he refused him. He did not cease speaking to him about it and mentioning the need to him, until he said to him: "Cast his earnings into the belly of your water-carrying camel."