Sahih Bukhari Volume 003, Book 034, Hadith Number 438.
Narated By Jabir bin 'Abdullah : I heard Allah's Apostle, in the year of the Conquest of Mecca, saying, "Allah and His Apostle made illegal the trade of alcohol, dead animals, pigs and idols." The people asked, "O Allah's Apostle! What about the fat of dead animals, for it was used for greasing the boats and the hides; and people use it for lights?" He said, "No, it is illegal." Allah's Apostle further said, "May Allah curse the Jews, for Allah made the fat (of animals) illegal for them, yet they melted the fat and sold it and ate its price."