Chapter on What is Permissible to Pray in, from Clothing and Place, and What is Not Permissible to Pray in, from That

Muhammad ibn Ya‘qub, from Ahmad ibn Idris, from Muhammad ibn Abdul-Jabbar, who said: I wrote to Abu Muhammad عليه السلام, peace be upon him, asking Him عليه السلام: "Is it permissible to pray in a cap made of pure silk or a cap made of brocade (dibaj)?" Imam عليه السلام wrote in reply: "Prayer is not permissible in pure silk."