Sahih al-Bukhari 6705
صحيح البخاري#6705SahihNarrated `Abdullah bin `Umar: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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 83:82