Sahih al-Bukhari 6499
صحيح البخاري#6499SahihNarrated Jundub:The Prophet (ﷺ) said, "He who lets the people hear of his good deeds intentionally, to win their praise, Allah will let the people know his real intention (on the Day of Resurrection), and he who does good things in public to show off and win the praise of the people, Allah will disclose his real intention (and humiliate him)
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: 81:88