Musnad Abu Ya'la al-Mawsili 111:31

Abu Ya'la informed us, Muhammad ibn 'Uqbah al-Sadusi narrated to us, Ali Abu Muhammad al-Qurashi narrated to us, Abu 'Abd al-Rahman al-Ghanawi narrated to us, from 'Abd al-Malik ibn 'Umayr, who said: I saw the head of al-Husayn ibn 'Ali when it was brought to 'Ubayd Allah ibn Ziyad. And I saw the head of 'Ubayd Allah ibn Ziyad when it was brought to al-Mukhtar ibn Abi 'Ubayd. And I saw the head of al-Mukhtar when it was brought to Mus'ab ibn al-Zubayr. And I saw the head of Mus'ab when it was brought to 'Abd al-Malik ibn Marwan. Abu Ya'la said: These people had no work other than [dealing with] heads.