question #1 Sahih al-Bukhari 952, Book 13, Hadith 4 : What is the significance of celebrating Eid in Islam according to the teachings of the Prophet Muhammad (ﷺ)?

Abu Bakr came to my house while two small Ansari girls were singing beside me the stories of the
Ansar concerning the Day of Buath. And they were not singers. Abu Bakr said protestingly, “Musical
instruments of Satan in the house of Allah’s Messenger (ﷺ) !” It happened on the `Id day and Allah’s Messenger (ﷺ)
said, “O Abu Bakr! There is an `Id for every nation and this is our `Id.”