It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) forbade the sale of Habl al-Habla. This was a transaction prevalent in the days of ignorance, in which a man would buy a she-camel on the condition that when the she-camel gives birth, and then that offspring gives birth, only then will he pay the price.