Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: The Prophet Muhammad (peace and blessings be upon him) forbade the sale of the unborn offspring of an unborn animal. In the days of ignorance, people used to make such transactions. A person would buy a she-camel on the condition that when this she-camel gives birth, and then the offspring in her womb also gives birth (then the payment will be made). (Imam Ibn Hibban, may Allah have mercy on him, says:) The prohibition of selling the unborn offspring of an unborn animal means: A person buys a camel on the condition that he will pay its full price when a certain she-camel gives birth, and then the offspring to be born also gives birth, so this would be the fixed term. There are two types of harm in this. Therefore, it is not permissible to act upon it.