Musannaf Ibn Abi Shayba 27:837

Suwayd al-Kalbi narrated to us, he said: Abd al-Aziz ibn Abi Salamah narrated to us, Muhammad ibn Abd Allah informed us that Kathir ibn al-Salt said: A freed slave of ours, who was an Arab, committed an offense. He came to Umar ibn Abd al-Aziz and sought help against him. He (Umar) said: "By Allah, the freed slave of the family of Kathir has indeed exceeded his bounds."