What are the consequences of accidentally hitting someone with a car and leaving them unconscious without knowing their fate? Is expiation (kaffarah) or blood money (diyah) obligatory, and if so, what is its amount and to whom should it be paid?

If traffic accidents result in wrongful death due to the driver's negligence or dereliction of duty, expiation (kaffarah) and blood money (diyah) are obligatory upon the driver, with the diyah borne by his 'aqilah (male relatives on the father's side). However, if the driver took all safety precautions and was not negligent, then neither diyah nor kaffarah is obligatory.

If the questioner is unable to ascertain the outcome of the accident, specifically whether it resulted in death or not, then neither diyah nor kaffarah is obligatory, because the fundamental principle is the presumption of innocence (bara'at al-dhimmah). Nevertheless, he must seek Allah's forgiveness and repent to Him, and increase in righteous deeds, as it was incumbent upon him to know the outcome of the accident in order to fulfill the rights due.

Financial rights must be restored to their owners if possible. If he is unable, he should seek their forgiveness, or give charity on their behalf if they are absent or deceased. Otherwise, he must increase in good deeds and supplicate to Allah to satisfy the rightful claimants on the Day of Resurrection.