Abu Ubayd (may Allah have mercy on him) says: I attended the Eid prayer with Sayyiduna Umar bin al-Khattab, Sayyiduna Uthman bin Affan and Sayyiduna Ali bin Abi Talib (may Allah be pleased with them), and in those days Sayyiduna Uthman (may Allah be pleased with him) was under siege.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5855