Surah An-Nisa, verse 12
12. And for you is half of what your wives leave if they have no child. But if they have a child, for you is one fourth of what they leave, after any bequest they [may have] made or debt. And for them [i.e., the wives] is one fourth if you leave no child. But if you leave a child, then for them is an eighth of what you leave, after any bequest you [may have] made or debt. And if a man or woman leaves neither ascendants nor descendants but has a brother or a sister, then for each one of them is a sixth. But if they are more than two, they share a third, after any bequest which was made or debt, as long as there is no detriment [caused]. [This is] an ordinance from Allāh, and Allāh is Knowing and Forbearing.
Mahmoud Khalil Al-Hussary
Explanation of the verse
You have half of what your wives leave, if they have no child. If they have a child, whether it is your child or not, then you get a fourth of the wealth they leave, after any bequest they have made and the repayment of any debts they had. Wives get a quarter of what you leave, if you have no child, whether it is their child or not. If you have a child, then they get an eighth of what you leave, after any bequest you have made and the repayment of any debts you had. If someone dies without any parents or children to inherit from them, but they have a brother or sister from the same mother as them, then each of them gets a sixth. If they have more than one brother or sister from the same mother as them, then they share a third, with brothers and sisters receiving the same share – this is after any bequest that they leave and the repayment of any debts they had, with the condition that the bequest does not cause harm to any of the inheritors, such as it being more than a third of the total of the wealth. The rulings contained in the verses about inheritance law are an obligation on you, and Allah knows what is in the interests of His servants in this world and the Afterlife. He is forbearing, and not quick to punish.