What is the ruling on the compulsory bequest (inheritance of a grandson from his paternal grandfather in the event of his father's death during the grandfather's lifetime) and what are its proofs?

The views of scholars regarding wills (wasiyya) can be summarized as follows: The majority of them hold that it is recommended, unless a right pertaining to Allah or to people is attached to it, in which case it becomes obligatory. However, some of the Salaf (early Muslims) deemed it obligatory for anyone who leaves behind wealth, and this is the view of Ibn Hazm.

The opinion of the majority of scholars is preferred, as they have agreed that a will is not obligatory except for someone who has outstanding rights without clear evidence.

As for the Egyptian law of wills, it has made wills obligatory for the first degree of descendants, namely the children of daughters and the children of sons, no matter how far down the lineage, for an amount equivalent to their father's share had he been alive, and within the limit of one-third, provided that the grandchild does not inherit.

The law relies on those among the Salaf who made wills obligatory, but the Salaf did not restrict it to grandchildren or estimate it by the father's share.

An objection to the law is that there may be non-inheriting relatives who are more in need than the grandchildren, and its application can lead to anomalous situations, such as a daughter's daughter receiving more than a son's daughter, or a son's daughter receiving more than the daughter.

The summary's author believes that the correct view is that of the majority of scholars, and that the law of obligatory wills deviates from the consensus of the majority and from those who made wills obligatory for non-inheriting relatives.

Despite wills not being obligatory, the wealthy individual is urged not to forget their needy relatives, especially non-inheriting grandchildren, and it is recommended to bequeath to them an amount not exceeding one-third of the estate.