Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) was asked about a daughter, a son's daughter and a sister, and he said: "For the daughter a half and for the sister a half." And he said: "Go to Ibn Mas'ud (may Allah be pleased with him); he will say the same as me." So Ibn Mas'ud (may Allah be pleased with him) was asked about it and was also told what Abu Musa (may Allah be pleased with him) had said. He said: "Then I would have gone astray and would not be among the rightly guided. I will judge in it with what the Messenger of Allah (peace and blessings be upon him) judged: 'For the daughter a half, for the son's daughter a sixth to complete the two-thirds, and what remains is for the sister.'" The narrator said: We went to Abu Musa (may Allah be pleased with him) and told him what Ibn Mas'ud (may Allah be pleased with him) had said, and he said: "Do not ask me about anything as long as this learned scholar is among you."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12310