And 'Amr al-Naqid and Ibn Abi 'Umar narrated to us, both saying: Sufyan narrated to us. And Ibn al-Muthanna narrated to us: 'Abd al-Wahhab narrated to us, all from Yahya ibn Sa'id, with this chain of transmission, and both said: "Just as the bellows removes the impurity." They did not mention "iron."