Chapter on Amount of Fitrah

And as for what Muhammad ibn Ahmad ibn Yahya narrated from Muhammad ibn Isa, from Muhammad ibn al-Rayyan, who said: I (narrator) wrote to the man (Imam عليه السلام), peace be upon him, asking Imam عليه السلام about ‘the Fitrah and its Zakat, how much is to be paid?’ Imam عليه السلام wrote: “Four artal according to the Madani measure.”