It is narrated from Amr bin Maymoon that he was present with Sayyiduna Umar (may Allah be pleased with him). He (may Allah be pleased with him) gathered the companions during his life and in a state of health, and asked them by invoking Allah, "Has anyone heard any hadith from the Messenger of Allah (peace and blessings be upon him) regarding the inheritance of the grandfather?" Sayyiduna Ma'qil bin Yasar (may Allah be pleased with him) stood up and said: "I heard from the Messenger of Allah (peace and blessings be upon him) that a case was brought to him in which there was a grandfather, so he (peace and blessings be upon him) gave the grandfather one-sixth or one-third share." Sayyiduna Umar (may Allah be pleased with him) asked: "What was that case, i.e., who were the individuals involved in that case?" He said: "That I do not know." He (may Allah be pleased with him) said: "What prevented you from knowing that?"
Hadith Takhrij«اسناده حسن۔ أخرجه ابن ماجه: 2722 ، (انظر مسند أحمد ترقيم الرسالة: 20309 ترقیم بيت الأفكار الدولية: 20575»
Brief Explanation
Benefits: … Along with knowing the share of any heir, it is also necessary to know in the presence of which other heirs this share is given to him; otherwise, the matter will remain incomplete and there will be no scholarly benefit. For example, the following are various scenarios regarding the grandfather:
(1) When the father is present, the grandfather receives nothing. (2) Every nearer grandfather excludes the more distant grandfather. (3) When the father is not present and there are male descendants of the deceased who are heirs, the grandfather will receive one-sixth. (4) When the father is not present and the only heirs from the descendants of the deceased are female, the grandfather will receive one-sixth and will also become an agnatic heir (asaba). (5) When neither the father is present nor are there any descendants of the deceased who are heirs, the grandfather will only become an agnatic heir (asaba).
Reflect that out of these five scenarios, only in one case does the grandfather become entitled solely to one-sixth. Therefore, it is necessary to have knowledge of both the share of the heir and also to know in the presence of which other heirs this share will be given.