Muhammad ibn Ya‘qub from Sahl from some of his companions from Al-Hasan Al-Jahm, who said: I said to Abu Al-Hasan Al-Ridha عليه السلام, peace be upon him: “I pass through the market and buy leather socks (khuff), and I do not know whether they are from a ritually slaughtered animal (dhaki) or not.” Imam عليه السلام said: “Pray in them.” I asked: “And what about sandals?” Imam عليه السلام said: “The same applies.” I said: “This makes me uneasy.” (concerning the purity of the leather) Imam عليه السلام said: “Do you turn away from us? Abu Al-Hasan عليه السلام, peace be upon him used to do that.”