The Islamic system of property distribution after death is based on rulings ordained by God in the Qur'an. It abolished the former custom in which the entire estate was taken by the oldest male heir and established the right of children, parents and spouses to inherit a specific share without leaving the matter to human judgement and emotion. When Islam established inheritance for the woman, it was the first time in history that women were able to enjoy this right. The Qur'an stipulates that a woman automatically inherits from her father, husband, son and her childless brother.
This system of inheritance is perfectly balanced and is based on the closeness of relationship, also taking into account the responsibilities imposed upon various members of a family in different situations. In the absence of close relatives a share is apportioned to more distant ones.
When the male is given a larger share, there is a logical reason behind it, which is that in Islam economic responsibility is always upon the man while the woman has no financial obligations, even if she should be wealthy or have her own income. Generally, the woman is in charge of running the household and taking care of those within it, so she is justly freed from financial responsibilities. When unmarried, it is the legal obligation of her father, brother or guardian to provide her food, clothing, medication, housing and other needs. After marriage it becomes the duty of her husband or adult son. Islam holds men responsible by law for fulfilling all the needs of their families. So the difference in shares does not in any way mean that one sex is preferred over the other. Rather, it represents a just balance consistent with the needs and responsibilities of family members.
When a son and a daughter inherit from either of their parents, the son's share will be depleted by giving an obligatory dowry to his wife upon marriage and maintaining his family, including his sister until she marries. While the daughter has no required expenses, she still receives a share of the inheritance which is her own property to save, invest or use as she pleases. When she marries, she will also receive a dowry from her husband and be maintained by him, having no financial responsibilities whatsoever. Thus, one might conclude that Islam has favored women over men!
Although, in most cases the male inherits a share that is twice that of a female, it is not always so. There are certain circumstances when they inherit equal shares, and in a few instances a female can inherit a larger share than that of the male.
In addition, a Muslim can will up to one third of his property by bequest to anyone who would not inherit from him by law. The bequest may be a means of assistance to other relatives and people who are in need, whether men or women. One may also allocate this portion or part of it to charities and good works of his choice.