The person about whom Allah's Messenger (ﷺ) said, "If I were to take a Khalil from this nation (my followers), then I would have taken him (i.e., Abu Bakr), but the Islamic Brotherhood is better (or said: good)," regarded a grandfather as the father himself (in inheritance).
Sahih al-Bukhari Book 85, Hadith 15
← Previous Hadith The Prophet (ﷺ) said, "Give the Fara'id, (the shares prescribed in the Qur'an) to those who are entitled to receive it, and then whatever remains, should be given to the closest male relative of the deceased."

Sahih al-Bukhari Book 85, Hadith 14 Next Hadith → (During the early days of Islam), the inheritance used to be given to one's offspring and legacy used to be bequeathed to the parents, then Allah cancelled what He wished from that order and decreed that the male should be given the equivalent of the portion of two females, and for the parents one-sixth for each of them, and for one's wife one-eighth (if the deceased has children) and one-fourth (if he has no children), for one's husband one-half (if the deceased has no children) and one-fourth (if she has children).

Sahih al-Bukhari Book 85, Hadith 16