Musnad Ahmad 1086:10

Yazid narrated to us, Ibn Abi Dhi'b informed us, from al-Zuhri, from Haram ibn Muhayyisah, from his father, that he asked the Prophet, peace and blessings of Allah be upon him, about the earnings of a cupper. He forbade him from it. He then mentioned his need to him, so he said: "Feed it to your camels used for watering."