Musnad Abu Ya'la al-Mawsili 7:27

Abu Khaythama narrated to us, Sufyan ibn 'Uyaynah narrated to us, from 'Amr, who heard Bajala say: I was a scribe for Juz' ibn Mu'awiyah, the paternal uncle of al-Ahnaf. A letter from 'Umar reached us one year before his death, saying: "Kill every sorcerer, separate every person with a prohibited relative among the Magians, and forbid them from the *zamzama* (muttering/chanting during meals)." So we killed three sorceresses, and we began to separate the man and his prohibited female relative according to the Book of Allah. He (Juz') prepared much food and invited the Magians, and he placed a sword upon his thigh. They threw down a mule-load or two of silver, and they ate without *zamzama*. 'Umar had not taken the *jizya* (poll tax) from the Magians until 'Abd al-Rahman ibn 'Awf informed him that the Messenger of Allah (peace be upon him) had taken it from the Magians of Hajar.