Sahih Muslim | Book 10 | Chapter 3

Narrated by 'Abdullah (b. 'Umar) (Allah be pleased with him)
'Abdullah (b. 'Umar) (Allah be pleased with him) said that Allah's Messenger (may peace be upon him) forbade the transaction called habal al-habala.

Narrated by Ibn 'Umar (Allah be pleased with them)
Ibn 'Umar (Allah be pleased with them) reported that the people of pre-Islamic days used to sell the meat of the slaughtered camel up to habal al-habala. And habal al-habala implies that a she-camel should give birth and then the (born one should grow young) and become pregnant. Allah's Messenger (may peace be upon him) forbade them that (this transaction).