Sura al-Nisāʾ 4:12

وَلَكُمْ نِصْفُ مَا تَرَكَ أَزْوَٰجُكُمْ إِن لَّمْ يَكُن لَّهُنَّ وَلَدٌ فَإِن كَانَ لَهُنَّ وَلَدٌ فَلَكُمُ ٱلرُّبُعُ مِمَّا تَرَكْنَ مِنۢ بَعْدِ وَصِيَّةٍ يُوصِينَ بِهَآ أَوْ دَيْنٍ وَلَهُنَّ ٱلرُّبُعُ مِمَّا تَرَكْتُمْ إِن لَّمْ يَكُن لَّكُمْ وَلَدٌ فَإِن كَانَ لَكُمْ وَلَدٌ فَلَهُنَّ ٱلثُّمُنُ مِمَّا تَرَكْتُم مِّنۢ بَعْدِ وَصِيَّةٍ تُوصُونَ بِهَآ أَوْ دَيْنٍ وَإِن كَانَ رَجُلٌ يُورَثُ كَلَٰلَةً أَوِ ٱمْرَأَةٌ وَلَهُۥٓ أَخٌ أَوْ أُخْتٌ فَلِكُلِّ وَٰحِدٍ مِّنْهُمَا ٱلسُّدُسُ فَإِن كَانُوٓا۟ أَكْثَرَ مِن ذَٰلِكَ فَهُمْ شُرَكَآءُ فِى ٱلثُّلُثِ مِنۢ بَعْدِ وَصِيَّةٍ يُوصَىٰ بِهَآ أَوْ دَيْنٍ غَيْرَ مُضَآرٍّ وَصِيَّةً مِّنَ ٱللَّـهِ وَٱللَّـهُ عَلِيمٌ حَلِيمٌ

wa-lakum niṣfu mā taraka azwājukum in lam yakun lahunna waladun fa-in kāna la-hunna waladun falakumu l-rubuʿu mimmā tarakna min baʿdi waṣīyatin yūṣīna bihā aw daynin wa-lahunna l-rubuʿu mimmā taraktum in lam yakun la-kum waladun fa-in kāna la-kum waladun fa-la-hunna l-thumunu mimmā taraktum min baʿdi waṣīyatin tūṣūna bihā aw daynin wa-in kāna rajulun yūrathu kalālatan awi imraʾatun wa-lahu akhun aw ukhtun falikulli wāḥidin minhumā l-sudusu fa-in kānū akthara min dhālika fa-hum shurakāʾu fī l-thuluthi min baʿdi waṣīyatin yūṣa bihā aw daynin ghayra muḍārrin waṣīyatan mina allāhi wallāhu ʿalīmun ḥalīmun

In what your wives leave, your share is a half, if they leave no child; but if they leave a child, ye get a fourth; after payment of legacies and debts. In what ye leave, their share is a fourth, if ye leave no child; but if ye leave a child, they get an eighth; after payment of legacies and debts. If the man or woman whose inheritance is in question, has left neither ascendants nor descendants, but has left a brother or a sister, each one of the two gets a sixth; but if more than two, they share in a third; after payment of legacies and debts; so that no loss is caused (to any one). Thus is it ordained by Allah; and Allah is All-knowing, Most Forbearing.