It is narrated from Mujahid that Abdullah bin Amr (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) "forbade the price of a dog, the earnings of a prostitute, the fee of a soothsayer and the earnings of a cupper."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11017