the father or the mother—even when they are higher up the ancestral line of grandfathers or grandmothers—kills his or her own son, grandson, or descendant; in that situation the diyah is trebled, because legal retaliation (qiṣāṣ) is barred in deliberate parricide.
Imām al-Shāfiʿī held that aggravation applies only to accidental homicide when the killing occurs within the Sacred Precinct, during one of the sacred months, or involves a person related to the killer in a degree of kinship that makes marriage unlawful.
Imām Aḥmad maintained that the diyah is to be aggravated if the killing takes place in the Sacred Precinct, in a sacred month, or while the killer is in a state of iḥrām. This is the well-known view of the later Hanbalīs and is the position adopted in al-Iqnaʿ and al-Muntahā; within the school it counts as one of the distinctive rulings (mufradāt). The mode of aggravation is to add one-third of the diyah for each of those circumstances.
A second report from Aḥmad states that no aggravation is required at all. This was the choice of al-Khiraqī, Ibn Qudāmah in al-Mughnī, and the author of al-Sharḥ al-Kabīr, basing themselves on the plain wording of the verse: “Whoever kills a believer by mistake must set free a believing slave and pay blood money to his family” (al-Nisāʾ 92).
This indicates that the diyah is the same everywhere and under all conditions, which is also the outward purport of the prophetic reports, and it is this opinion that is applied in the Sharīʿah courts of the Kingdom of Saudi Arabia.
Note: According to the majority of jurists, aggravation applies only in cases of accidental killing, not in deliberate homicide.