Abu Ubaid, the freed slave of Abdur-Rahman bin Awf narrated:"I witnessed Umar bin Al-Khattab on the Day of Nahr beginning with the Salat before the Khutbah. Then he said: 'I heard the Messenger of Allah prohibit fasting on these two days. As for the Day of Fitr, then it is for you to take a break from your fasting, and a celebration for the Muslims. As for the Day of Adha, then eat from the flesh that you have sacrificed

English translation · Jami' at-Tirmidhi