Sahih Muslim Book 1, Hadith Number 207.

Chapter : Suicide is the gravest sin.

It is reported on the authority of Hasan: A person belonging to the people of the past suffered from a boil, when it pained him, he drew out an arrow from the quiver and pierced it. And the bleeding did not stop till he died. Your Lord said: I forbade his entrance into Paradise. Then he (Hasan) stretched his hand towards the mosque and said: By God, Jundab transmitted this hadith to me from the Messenger of Allah (may peace be upon him) in this very mosque.