Laws of Inheritance (Al-Faraa'id)
حَدَّثَنِي عَمْرُو بْنُ عَبَّاسٍ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ، حَدَّثَنَا سُفْيَانُ، عَنْ أَبِي قَيْسٍ، عَنْ هُزَيْلٍ، قَالَ قَالَ عَبْدُ اللَّهِ لأَقْضِيَنَّ فِيهَا بِقَضَاءِ النَّبِيِّ صلى الله عليه وسلم لِلاِبْنَةِ النِّصْفُ، وَلاِبْنَةِ الاِبْنِ السُّدُسُ، وَمَا بَقِيَ فَلِلأُخْتِ.Narrated Huzail:`Abdullah said, "The judgment I will give in this matter will be like the judgment of the Prophet, i.e. one-half is for the daughter and one-sixth for the son's daughter and the rest of the inheritance for the sister
From Sahih al-Bukhari, whose reports the scholars accept as authentic.