Narrated Ibn `Abbas:
The Prophet (ﷺ) said, "No good deeds done on other days are superior to those done on these (first ten days of Dhul Hijja)." Then some companions of the Prophet (ﷺ) said, "Not even Jihad?" He replied, "Not even Jihad, except that of a man who does it by putting himself and his property in danger (for Allah's sake) and does not return with any of those things."
Narrated Abu `Ubaid:
(the slave of Ibn Azhar) I witnessed the `Id with `Umar bin Al-Khattab who said, Allah's Messenger (ﷺ) has forbidden people to fast on the day on which you break fasting (the fasts of Ramadan) and the day on which you eat the meat of your sacrifices (the first day of `Id ul Fitr and `Id ul-Adha).
Narrated Abu `Ubaid:
the freed slave of Ibn Azhar that he witnessed the Day of `Id-al-Adha with `Umar bin Al-Khattab. `Umar offered the `Id prayer before the sermon and then delivered the sermon before the people, saying, "O people! Allah's Messenger (ﷺ) has forbidden you to fast (on the first day of) each of these two 'Ida, for one of them is the Day of breaking your fast, and the other is the one, on which you eat the meat of your sacrifices."
Abu Ubaid, the freed slave of Ibn Azhar, reported: I observed Id along with Umar b. al-Khattab (Allah be pleased with him). He came (out in an open space) and prayed and (after) completing it addressed the people and said: The Messenger of Allah (ﷺ) has forbidden the observing of fast on these two days. One is the day of Fitr (at the end of your fasts), and the second one, the day when you eat (the meat) of your sacrifices.