The custom (in old days) was that the property of the deceased would be inherited by his offspring; as for the parents (of the deceased), they would inherit by the will of the deceased. Then Allah cancelled from that custom whatever He wished and fixed for the male double the amount inherited by the female, and for each parent a sixth (of the whole legacy) and for the wife an eighth or a fourth and for the husband a half or a fourth.  

كَانَ الْمَالُ لِلْوَلَدِ وَكَانَتِ الْوَصِيَّةُ لِلْوَالِدَيْنِ فَنَسَخَ اللَّهُ مِنْ ذَلِكَ مَا أَحَبَّ فَجَعَلَ لِلذَّكَرِ مِثْلَ حَظِّ الأُنْثَيَيْنِ وَجَعَلَ لِلأَبَوَيْنِ لِكُلِّ وَاحِدٍ مِنْهُمَا السُّدُسَ وَجَعَلَ لِلْمَرْأَةِ الثُّمُنَ وَالرُّبْعَ وَلِلزَّوْجِ الشَّطْرَ وَالرُّبُعَ  

(In the Pre-Islamic Period ) the children used to inherit all the property but the parents used to inherit only through a will. So Allah cancelled that which He liked to cancel and put decreed that the share of a son was to be twice the share of a daughter, and for the parents one-sixth for each one of them, or one third, and for the wife one-eighth or one-fourth, and for the husband one-half, or one-fourth.  

كَانَ الْمَالُ لِلْوَلَدِ وَكَانَتِ الْوَصِيَّةُ لِلْوَالِدَيْنِ فَنَسَخَ اللَّهُ مِنْ ذَلِكَ مَا أَحَبَّ فَجَعَلَ لِلذَّكَرِ مِثْلَ حَظِّ الأُنْثَيَيْنِ وَجَعَلَ لِلأَبَوَيْنِ لِكُلِّ وَاحِدٍ مِنْهُمَا السُّدُسَ وَالثُّلُثَ وَجَعَلَ لِلْمَرْأَةِ الثُّمُنَ وَالرُّبُعَ وَلِلزَّوْجِ الشَّطْرَ وَالرُّبُعَ  

(During the early days of Islam), the inheritance used to be given to one's offspring and legacy used to be bequeathed to the parents, then Allah cancelled what He wished from that order and decreed that the male should be given the equivalent of the portion of two females, and for the parents one-sixth for each of them, and for one's wife one-eighth (if the deceased has children) and one-fourth (if he has no children), for one's husband one-half (if the deceased has no children) and one-fourth (if she has children).  

كَانَ الْمَالُ لِلْوَلَدِ وَكَانَتِ الْوَصِيَّةُ لِلْوَالِدَيْنِ فَنَسَخَ اللَّهُ مِنْ ذَلِكَ مَا أَحَبَّ فَجَعَلَ لِلذَّكَرِ مِثْلَ حَظِّ الأُنْثَيَيْنِ وَجَعَلَ لِلأَبَوَيْنِ لِكُلِّ وَاحِدٍ مِنْهُمَا السُّدُسُ وَجَعَلَ لِلْمَرْأَةِ الثُّمُنَ وَالرُّبُعَ وَلِلزَّوْجِ الشَّطْرَ وَالرُّبُعَ  

The custom (in old days) was that the property of the deceased would be inherited by his offspring; as for the parents (of the deceased), they would inherit by the will of the deceased. Then Allah cancelled from that custom whatever He wished and fixed for the male double the amount inherited by the female, and for each parent a sixth (of the whole legacy) and for the wife an eighth or a fourth and for the husband a half or a fourth. (Using translation from Bukhārī 2747)  

«كَانَ الْمَالُ لِلْوَلَدِ وَكَانَتِ الْوَصِيَّةُ لِلْوَالِدَيْنِ وَالْأَقْرَبِينَ فَنَسَخَ اللَّهُ مِنْ ذَلِكَ مَا أَحَبَّ فَجَعَلَ لِلذَّكَرِ مِثْلَ حَظِّ الْأُنْثَيَيْنِ وَجَعَلَ لِلْأَبَوَيْنِ لِكُلِّ وَاحِدٍ مِنْهُمَا السُّدُسَ وَالثُّلُثَ وَجَعَلَ لِلْمَرْأَةِ الثُّمُنَ وَالرُّبُعَ وَلِلزَّوْجِ الشَّطْرَ وَالرُّبُعَ»  

[Machine] In His saying, "Allah instructs you concerning your children: for the male, what is equal to the share of two females" [Quran 4:11], it is mentioned that inheritance was for the child and the will was for the parents. So, Allah abrogated from that which He preferred and made the share of the male child equal to two females, and He made for the parents one-sixth each, and He made for the husband half or one-fourth, and He made for the wife one-fourth or one-eighth.  

فِي قَوْلِهِ ﷻ {يُوصِيكُمُ اللهُ فِي أَوْلَادِكُمْ لِلذَّكَرِ مِثْلُ حَظِّ الْأُنْثَيَيْنِ} [النساء 11] قَالَ كَانَ الْمِيرَاثُ لِلْوَلَدِ وَكَانَتِ الْوَصِيَّةُ لِلْوَالِدَيْنِ فَنَسَخَ اللهُ مِنْ ذَلِكَ مَا أَحَبَّ فَجَعَلَ لِلْوَلَدِ الذَّكَرِ مِثْلَ حَظِّ الْأُنْثَيَيْنِ وَجَعَلَ لِلْوَالِدَيْنِ السُّدُسَيْنِ وَجَعَلَ لِلزَّوْجِ النِّصْفَ أَوِ الرُّبُعَ وَجَعَلَ لِلْمَرْأَةِ الرُّبُعَ أَوِ الثُّمُنَ