Sahih Bukhari Volume 6, Book 60, Hadith Number 440.

Narrated By Haritha bin Wahb Al-Khuzai : I heard the Prophet saying. “May I tell you of the people of Paradise? Every weak and poor obscure person whom the people look down upon but his oath is fulfilled by Allah when he takes an oath to do something. And may I inform you of the people of the Hell-Fire? They are all those violent, arrogant and stubborn people.”