What was the Prophet Muhammad (saw) prohibiting in the pre-Islamic period of ignorance?
 Narrated Ibn `Umar:                     In the pre-lslamic period of ignorance the people used to bargain with the meat of camels on the principle of Habal-al-Habala which meant the sale of a she-camel that would be born by a she-camel that had not yet been born. The Prophet forbade them such a transaction.