Narrated Jundub (Radi-Allahu ‘anhu):
The Prophet (Sallallahu ‘Alaihi Wa Sallam) 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).”
Bukhari Vol. 8 : No. 506
