An-Nisa

They ask you [Prophet] for a ruling. Say, ‘God gives you a ruling about inheritance from someone who dies childless with no surviving parents. If a man leaves a sister, she is entitled to half of the inheritance; if she has no child her brother is her sole heir; if there are two sisters, they are entitled to two-thirds of the inheritance between them, but if there are surviving brothers and sisters, the male is entitled to twice the share of the female. God makes this clear to you so that you do not make mistakes: He has full knowledge of everything.’