The Book of Transactions (Kitab Al-Buyu`)

Muslim :: Book 10 : Hadith 3805

Rafi b. Khadij (Allah be pleased with him) reported: I heard Allah's Apostle (may peace be upon him) as saying: The worst earning is the earning of a prostitute, the price of a dog and the earning of a cupper.

Source materials are from the University of Southern California MSA site
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