I wrote to Abu’l-Hasan, peace be upon him, on the hands of my father: May I be sacrificed for you, our companions have disputed with regards to (the measurement of) a ssaa’. Some of them say that (the alms tax of) the Fitra is (given by the amount of) a ssaa’ of Medina, and some of them say the ssaa’ of Iraq. Then he wrote to me: A ssaa’ is (consisting of) six pounds by the Medinian standard, and nine pounds by the Iraqi standard. He said: He also informed me and said: In measurement, it is one thousand and one hundred and seventy measures.