Types of Blood-Wit (Kitab Al-Diyat)
Dawud :: Book 39 : Hadith 4481
Narrated AbuShurayh al-Khuza'i:
The Prophet (peace_be_upon_him) said: If a relative of anyone is killed, or if he suffers khabl, which means a wound, he may choose one of the three things: he may retaliate, or forgive, or receive compensation. But if he wishes a fourth (i.e. something more), hold his hands. After this whoever exceeds the limits shall be in grave penalty.