Muhammad ibn Ahmad, from Jafar ibn Muhammad al-Hamdani, who said: I wrote to Abu al-Hasan عليه السلام, peace be upon him, through my father: “May I be made your ransom, our companions have differed concerning the sa’. Some of them say that the fitrah is by the Madinese sa’, and some of them say by the Iraqi sa’.” So the Imam عليه السلام, peace be upon him, wrote to me: “The sa’ is six rotls (artal) by the Madinese measure and nine rotls by the Iraqi measure.” He said: “And by weight it is one thousand, one hundred and seventy weights (waznah).”