Bukhari

Hadith Commentary:
The translation of the chapter heading is derived from the incident in which the Muslims, by mistake, killed the father of Hudhayfah radi Allahu anhu, who was a Muslim. Hudhayfah radi Allahu anhu forgave them and did not wish to demand blood money (diyah), but the Messenger of Allah sallallahu alayhi wa sallam arranged for the blood money to be given from his own side.

Hadith Commentary:
(1)
The Muslims, by mistake, martyred the noble father of Hudhayfah radi Allahu anhu, namely Yaman radi Allahu anhu. Since this killing occurred by mistake, after his martyrdom Hudhayfah radi Allahu anhu forgave the blood of his father. However, the Messenger of Allah sallallahu alayhi wa sallam, on his own behalf, paid the blood money (diyah) to Hudhayfah radi Allahu anhu.

(2)
Before death, the right to pardon belongs to the murdered person, that he may forgive his killer. For example, when Urwah ibn Mas’ud radi Allahu anhu invited his people to Islam, someone shot an arrow at him. When he was near death, he forgave his killer, and the Messenger of Allah sallallahu alayhi wa sallam upheld his pardon.

(3)
The position of the Ahl al-Zahir is that the murdered person has no right to pardon; rather, this right belongs to his heirs. However, this position is questionable, as is evident from the incident of Urwah ibn Mas’ud radi Allahu anhu. In any case, after death, the blood of the murdered person can be pardoned, and the right of pardon belongs to the heirs of the murdered person.
(Fath al-Bari: 12/263)