General Behavior (Kitab Al-Adab)
Dawud :: Book 41 : Hadith 4863
Narrated Al-Mustawrid:
The Prophet (peace_be_upon_him) said: If anyone eats once at the cost of a Muslim's honour, Allah will give him a like amount of Jahannam to eat; if anyone clothes himself with a garment at the cost of a Muslim's honour, Allah will clothe him with like amount of Jahannam; and if anyone puts himself in a position of reputation and show Allah will disgrace him with a place of reputation and show on the Day of Resurrection.