Qabisah bin Dhu'ayb al-Khuza'i said: A grandmother came to Sayyiduna Abu Bakr (may Allah be pleased with him) seeking her inheritance from (the estate of) her son or daughter. Sayyiduna Abu Bakr (may Allah be pleased with him) said: I do not find anything for you in the Book of Allah, nor have I heard the Messenger of Allah (peace and blessings be upon him) decide anything for you, and I will ask the people in the evening. When he had prayed the Zuhr prayer, he turned to the people and said: A grandmother has come to me asking about her inheritance from (the estate of) her son or daughter, and I have not found anything for her in the Book of Allah, nor have I heard the Messenger of Allah (peace and blessings be upon him) give any decision for her. Has any of you heard anything from the Messenger of Allah (peace and blessings be upon him) about this? Al-Mughirah bin Shu'bah (may Allah be pleased with him) stood up and said: "I saw the Messenger of Allah (peace and blessings be upon him) give her one sixth." So Sayyiduna Abu Bakr (may Allah be pleased with him) gave her one sixth. Then he asked: Did anyone else hear this along with you? Sayyiduna Muhammad bin Maslamah (may Allah be pleased with him) stood up and said: I too saw the Messenger of Allah (peace and blessings be upon him) give her one sixth. So Sayyiduna Abu Bakr (may Allah be pleased with him) gave her one sixth. When the caliphate of Sayyiduna Umar (may Allah be pleased with him) came, the grandmother from the other side (that is, the maternal grandmother) came to him, and Sayyiduna Umar (may Allah be pleased with him) said: That decision was for someone other than you, but if the two of you are together, the one sixth will be divided between you, and whichever of you is alone will receive all of it.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16559