Musnad Ahmad 25:224

Waki’ narrated to us, from Sufyan, from ‘Abd al-Rahman ibn ‘Abis, who said: I said to Ibn ‘Abbas: "Did you witness the ‘Eid with the Messenger of Allah, may Allah bless him and grant him peace?" He said: "Yes, and were it not for my position with him, I would not have witnessed it due to my young age." He said: "The Messenger of Allah, may Allah bless him and grant him peace, went out and prayed two rak'ahs at the house of Kathir ibn al-Salt, then he delivered a sermon. He did not mention an adhan or an iqamah."