Sayyiduna Abu Shurah Khuza'i (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him) saying: "If a person is killed or wounded, then he (or his heir) has the choice to accept one of three things. If he wishes to do a fourth, prevent him. These three things are: either he seeks retribution (qisas—retaliation in kind), or he forgives, or he accepts blood money (diyah). If he chooses one of these three and then seeks a fourth, then for him (the heir or the authority) is the fire of Hell, where he will abide forever."

Abu Bakr bin Amr bin Hazm narrates from his father, from his grandfather, that the Messenger of Allah (peace be upon him) wrote a document for the people of Yemen, and in that letter it was stated: "Whoever kills a Muslim without reason, and the murder is proven against him by witnesses, then retribution (qisas) is obligatory upon him (i.e., he will be punished in kind), unless the heirs of the slain are pleased (i.e., they forgive him)."
Imam Darimi (may Allah have mercy on him) said: The meaning of «اعتبط» is to kill without any excuse.