Sahih Bukhari
Virtues and Merits of the Prophet (pbuh) and his Companions
Volume: 004 / Book Number: 056 / Hadith Number: 669
Narrated Jundub:
Allah's Apostle said, "Amongst the nations before you there was a man who got a wound, and growing impatient (with its pain), he took a knife and cut his hand with it and the blood did not stop till he died. Allah said, 'My Slave hurried to bring death upon himself so I have forbidden him (to enter) Paradise.' "