Please explain the inheritance scenarios of the grandfather with full-siblings or half-siblings (from the father's side).

For anyone seeking to understand the issues of the grandfather with siblings in inheritance (fara'id), it is essential to grasp the general principles of fara'id. The preponderant opinion is that siblings are excluded by the grandfather, and this was the view of Abu Bakr Al-Siddiq and others. According to the other opinion, which is the madhhab of Malik, Al-Shafi'i, and Ahmad, the grandfather does not exclude siblings; rather, they inherit with him, and the grandfather is treated according to what is most beneficial for him.

There are two scenarios for the grandfather with siblings: 1. Absence of a fixed share heir (ashab al-furud): The grandfather inherits the greater of one-third of the estate or a proportional share (muqasama). 2. Presence of a fixed share heir: The fixed share heir takes their share, then the grandfather shares with the siblings, and the grandfather is treated according to what is most beneficial for him, whether it is a proportional share (muqasama), one-third of the remainder, or one-sixth of the entire estate.

Among the issues related to the grandfather and siblings are: 1. Al-Akdariya: This specific case involves a husband, a mother, a grandfather, and a full sister or a sister by the father. In this unique scenario, the sister takes half, the problem (masa'la) is subjected to 'awl (increase in the sum of shares, leading to proportional reduction of each share), and the shares of the grandfather and the sister are divided by ta'sib (residuary inheritance), with the male receiving a share equal to that of two females. 2. Al-Mu'addah: If a grandfather, full siblings, and paternal half-siblings are present, the paternal half-brother is counted as a full sibling (he is included in the count but does not inherit). Al-Mu'addah only applies if the most beneficial option for the grandfather is the proportional share (muqasama).