Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) led the people in prayer on the day of sacrifice. When he had finished the prayer and the sermon, he called for a ram and slaughtered it himself, and said: "'Bismillahi wallahu akbar' (In the name of Allah, and Allah is the Greatest). O Allah, (this is) on behalf of me and of whoever of my Ummah has not offered a sacrifice."
Imam al-Shafi'i (may Allah have mercy on him) said: It has reached us that Sayyiduna Abu Bakr al-Siddiq and Umar (may Allah be pleased with them both) did not offer sacrifices, fearing that people would follow their example and that whoever saw them would think it obligatory.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19033