Abd al-Malik, the son of Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him), said: I attended one of the two Eids with Sayyiduna Ka'b (may Allah be pleased with him). When the people returned (from the Eid prayer), most of them went to the mosque, and I saw that he (my father) was heading home. So I said: Father, will you not go to the mosque? I see the people heading there. He said: "Much of what you see is the result of harshness and little knowledge. These two rak'ahs (of Eid) are the voluntary worship of this day, until the (next) prayer calls you."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16376