Sahih al-Bukhari 5179
صحيح البخاري#5179SahihNarrated Nafi`:`Abdullah bin `Umar said, "Allah's Messenger (ﷺ) said, 'Accept the marriage invitation if you are invited to it.' " Ibn `Umar used to accept the invitation whether to a wedding banquet or to any other party, even when he was fasting
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: 67:114