Abu Mas'ud Uqbah bin Amr (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) forbade "the price of a dog, the earnings of a prostitute and the sweets (fee) of a soothsayer." In the narration of Yunus these words are additional: "These three earnings are unlawful."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النفقات / 15789