Is what Al-Qurtubi said regarding the creation of livestock in Paradise and then their descent to Earth, and his analogy to the Almighty’s saying: "And We sent down iron, wherein is great might," where iron descended with Adam (peace be upon him), definitively established and authentic, and is there a consensus on it, especially concerning the descent of livestock?

Al-Qurtubi stated that 'cattle were sent down' means they were created, or made, or given. This is because they are formed through vegetation, and vegetation through water sent down. Or, that when Adam descended, Allah sent down iron with him, and similarly with cattle. Or, that creation only occurs through a command that descends from the sky, and the meaning is: He created such-and-such for you by His descending command. Al-Qurtubi did not definitively assert any of these, but rather mentioned them as various opinions.