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 and his family) forbade fraudulent trade. Sayyiduna Ibn Umar (may Allah be pleased with them both) says: This was the method of trade among people in the Age of Ignorance; its form was that a person would sell a she-camel in exchange for the unborn offspring of another she-camel. The Messenger of Allah (peace and blessings be upon him and his family) forbade this.