What did the Jew compliment about the Holy Book of Muslims when he spoke to 'Umar bin Al-Khattab?
      Narrated 'Umar bin Al-Khattab:                          Once a Jew said to me, "O the chief of believers! There is a verse in      your Holy Book Which is read by all of you (Muslims), and had it been      revealed to us, we would have taken that day (on which it was revealed     as a day of celebration." 'Umar bin Al-Khattab asked, "Which is that      verse?" The Jew replied, "This day I have perfected your religion For      you, completed My favor upon you, And have chosen for you Islam as      your religion." (5:3) 'Umar replied,"No doubt, we know when and where      this verse was revealed to the Prophet. It was Friday and the Prophet      was standing at 'Arafat (i.e. the Day of Hajj)"