Saad bin Abu Ubayd reported,
I was present at the Eid prayer with Umar bin Khattab 
. He prayed before delivering the sermon, without any adhan or iqamah, and then he addressed the people, saying, "People, the Messenger of Allah ﷺ forbade fasting on these two days. One of them is the day you break your fast and celebrate your Eid, and the other is the day on which you eat from your sacrifice."
Ahmad 225
Sahihحدثنا يعقوب حدثنا أبي عن محمد بن إسحاق حدثنا الزهري عن سعد بن أبي عبيد مولى عبد الرحمن بن أزهر قال شهدت العيد مع عمر بن الخطاب رضي الله عنه فذكر الحديث
Its isnad is sahih.Abu Ubayd, the freed slave of Abdul-Rahman bin Awf, is Saad bin Ubayd, the freed slave of Ibn Azhar, one of the jurists of Madinah, unanimously agreed to be trustworthy. He lived during the time of the Prophet ﷺ, but no narration from him has been established as authentic.The second chain, in h, reads, Zuhri from Saeed from Saad bin Abu Ubayd, which is an error. We corrected it from k and h. This hadith is a repetition of 163.