Abu Ubayd reported,
He was present at the Eid prayer with Umar bin Khattab 
, who prayed before delivering the sermon, without any call to prayer or iqamah. Then Umar gave the sermon and said, "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 sacrifices."
Ahmad 224
Sahihحدثنا عبد الرزاق أنبأنا معمر عن الزهري
عن أبي عبيد مولى عبد الرحمن بن عوف
أنه شهد العيد مع عمر بن الخطاب رضي الله عنه فصلى قبل أن يخطب بلا أذان ولا إقامة ثم خطب فقال يا أيها الناس إن رسول الله ﷺ نهى عن صيام هذين اليومين أما أحدهما فيوم فطركم من صيامكم وعيدكم وأما الآخر فيوم تأكلون فيه من نسككم
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.