Here we go :
(This is from sahih muslim)
Chapter 30: The price of a dog, the sweets of a kahin,
the earnings of a prostitute and the selling of a cat
all forbidden
Book 010, Number 3803:
Aba Mas'ud al-Ansari (Allah be pleased with him) reported that Allah's Messenger (may peace be
upon him) forbade the charging of price of the dog, and earnings of a prostitute and sweets offered
to a kahin.
Book 010, Number 3804:
A hadith like this is reported on the authority of Abu Mas'ud through another chain of transmitters.
Book 010, Number 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.
Book 010, Number 3806:
Rafi b. Khadij reported Allah's Messenger (may peace be upon him) as saying: The price of a dog is
evil, the earning of a prostitute is evil and the earning of a cupper is evil.
Book 010, Number 3807:
A hadith like this has been narrated on the authority of Rifi' b. Khadlj through another chain of
transmitters.
Book 010, Number 3808:
Abu Zubair said: I asked Jabir about the price of a dog and a cat; he said: Allah's Messenger (may
peace be upon him) disapproved of that.