‏البيوع : Hadeeth No:3805 Rafi b. Khadij (Allaah be pleased with him) reported: I heard Allaah's Prophet (sallAllaahu alayhi wa sallam) as saying: The worst earning is the earning of a prostitute, the price of a dog and the earning of a cupper....

‏العلم : Hadeeth No:6455 This hadith has been narrated on the authority of 'Abdullah (b. Mas'ud) and Abu Musa (al-Asha'ri) through other chains of transmitters....