Musannaf Ibn Abi Shayba 37:572

Narrated to us Kathir ibn Hisham, from Ja'far ibn Burqan, who said: Narrated to us al-'Ala' ibn 'Abd Allah ibn Rafi', from Maymun, who said: When 'Uthman was killed, Hudhayfah did like this—and he made a circle with his hand—and said: "A rift has been opened in Islam, a rift that no mountain can mend."