Mustadrak al-Hakim — Hadith 3248

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that a man came to him and said: "A man has died and left behind a daughter and a full sister (from both father and mother)?" He said: "The daughter gets half and the sister gets nothing; whatever remains belongs to his (other) agnatic heirs ('asabah)." Upon this a man said to him: "But Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) judged otherwise: he gave half to the daughter and half to the sister." Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: "Do you know better, or Allah?" Ma'mar said: I did not understand the reason for this until I met Ibn Tawus. I mentioned this hadith of al-Zuhri to him, and he said: My father informed me that he heard Ibn Abbas (may Allah be pleased with them both) say that Allah Almighty has said: "If a man dies having no child and he has a sister, then she gets half of what he left" [Surah an-Nisa: 176]. Ibn Abbas (may Allah be pleased with them both) said: "Yet you people say that she (the sister) gets half even if he (the deceased) has a child!"
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.