Muwatta Malik

Yahya related to me from Malik from Abu'z-Zinad that Said ibn al- Musayyab said, ""Bartering live animals for dead meat is forbidden."" Abu'z-Zinad said, ""I said to Said ibn Musayyab, 'What do you think of a man buying an old camel for 10 sheep?' "" Said said, ""If he buys it to slaughter it, there is no good in it."" Abu'z-Zinad added, ""All the people (i.e. companions) that I have seen forbade bartering live animals for meat."" Abu'z-Zinad said, ""This used to be written in the appointment letters of governors in the time of Aban ibn Uthman and Hisham ibn Ismail