of Bilad al-Sham . The Arab Muslim historian Musa b. 'Uqba (d. 758) recorded that caliph Umar ibn al-Khattab exiled the Jews and Christians of Khaybar to Jericho (and Tayma). [ 28 ] By 659 that district had come under the control of Mu'awiya , founder of the Umayyad dynasty .