Musannaf Ibn Abi Shayba 3:3461

Abu al-Ahwas narrated to us, from Abd al-A’la, from Abu Abd al-Rahman, who said: Two Eids coincided during the time of Ali. He prayed with the people, then he delivered a sermon while on his mount and said: "O people, whoever among you has attended the Eid, he has fulfilled his Jumu'ah, if Allah wills."