What did the Prophet Muhammad (peace be upon him) approximate with his two fingers to illustrate how much wearing of silk was allowed?
 Narrated Abu `Uthman:                     While we were at Adharbijan, `Umar wrote to us: 'Allah's Apostle forbade wearing silk except this much. Then the Prophet approximated his two fingers (index and middle fingers) (to illustrate that) to us.' Zuhair (the sub-narrator) raised up his middle and index fingers.