Maliks Muwatta Book 31, Hadith Number 62.
Section : What Is Not Permitted in the Sale of Animals.
Yahya related to me from Malih from Nafi from Abdullah ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, forbade the transaction called habal alhabala. It was a transaction which the people of Jahiliya practised. A man would buy the unborn offspring of the unborn offspring of a she-camel.