Musnad Abu Ya'la al-Mawsili 110:9

Ja'far ibn Humayd al-Kufi narrated to us, Sharik narrated to us, from Simak, from Ikrimah, from Ibn Abbas, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "There is no confederacy (hilf) in Islam. And whatever was (established) in the Jahiliyyah, Islam has only increased it in strength or firmness."