The Prophet ﷺ was asked about the earnings of a cupper, and he said, "Feed it to your camel."
حدثنا سفيان عن أبي الزبير سمع
إن النبي ﷺ سئل عن كسب الحجام فقال اعلفه ناضحك
Its isnad is sahih, mentioned previously at 14224.