that he was asked about a man who had vowed that he would fast all the days of his life then the day of `Id al Adha or `Id-al-Fitr came. `Abdullah bin `Umar said: You have indeed a good example in Allah's Messenger (ﷺ). He did not fast on the day of `Id al Adha or the day of `Id-al-Fitr, and we do not intend fasting on these two days.
Sahih al-Bukhari Book 83, Hadith 82
← Previous Hadith While the Prophet (ﷺ) was delivering a sermon, he saw a man standing, so he asked about that man. They (the people) said, "It is Abu Israil who has vowed that he will stand and never sit down, and he will never come in the shade, nor speak to anybody, and will fast.'' The Prophet (ﷺ) said, "Order him to speak and let him come in the shade, and make him sit down, but let him complete his fast."

Sahih al-Bukhari Book 83, Hadith 81 Next Hadith → I was with Ibn `Umar when a man asked him, "I have vowed to fast every Tuesday or Wednesday throughout my life and if the day of my fasting coincided with the day of Nahr (the first day of `Id-al- Adha), (What shall I do?)" Ibn `Umar said, "Allah has ordered the vows to be fulfilled, and we are forbidden to fast on the day of Nahr." The man repeated his question and Ibn `Umar repeated his former answer, adding nothing more.

Sahih al-Bukhari Book 83, Hadith 83