Abu Dawud Book 34, Hadith Number 4486.

Chapter : If authorities ask relatives of a slain to forgo their right what should they do.

Narated By Wa’il ibn Hujr : A man brought an Abyssinian to the Prophet (PBUH) and said: This man has killed my nephew. He asked: How did you kill him? He replied: I struck his head with an axe but I did not intend to kill him. He asked: Have you some money so that you pay his blood-wit? He said: No. He said: What is your opinion if I send you so that you ask the people (for money) and thus collect your blood-wit? He said: No. He said: Will your masters give you his blood-wit (to pay his relatives)? He said: No. He said to the man. Take him. So he brought him out to kill him. The Apostle of Allah (peace be upon him) said: If he kills him, he will be like him. This (statement) reached the man where he was listening t the statement. He said: He is here; order regarding him as you like. The Apostle of Allah (PBUH) said: Leave him alone. And he once said: He will bear the burden of the sin of the slain and his own and thus he will become one of the companions of Hell. So let him go.