Ali ibn Muhammad from Ali ibn Al-Rayan, who said: Some of our companions wrote with the hand of Ibrahim ibn Uqbah to Imam عليه السلام, meaning Abu Ja'far, peace be upon him, asking Him عليه السلام about prayer upon the khumrah of Madinah. So He عليه السلام wrote: "Pray upon it as long as it is made with threadwork, and do not pray upon that which is made with leather straps." He said: Then our companions hesitated, so I recited to them a line of poetry by Ta'abbata Sharran Al-Fihmi: "As if it were the threadwork of a Mari, twisted and spun," and Mari is a man who makes ropes and twists threads.