[4:11] God charges you concerning your children, to the male the equivalent of the portion of two females; and if they be women more than two, then for them two-thirds of what he leaves; but if she be one then to her a half; and to his parents, to each one of the two the sixth of what he leaves, if he has a child; but if he has no child, and his heirs are his parents, then to his mother a third; or, if he has siblings, to his mother a sixth after any bequest that he may bequeath, or any debt.
Thc word 'charge' (waṣiyya) here means 'command'. He (s) set the terms of the inheritance among the inheritors for what is due from two aspects - the apportioning and the inheritance by the group of relatives (taʿṣīb). The inheritance by the group of relatives is stronger than the apportioning because it comprises all of the wealth whereas the greater part of the portions cannot exceed two-thirds [of the estate]. Therefore, the division [of the estate] begins with those who possess of the ordained portions and they are they weakest in terms of entitlement while the group of relatives (ʿaṣaba) has the stronger right. [The Prophet] (ṣ) said: Whatever remains of the portions goes to the nearest male relative. Thus is His way (sunna) forever, just as in [God] Most High's words: Then We bequeathed the Book to those of Our servants whom We chose. [35:32] We gave them the Book as the inheritance. Then He showed preference for the wrongdoer over those who take the lead. [Those who take the lead] are weaker in their claims for the showing of generosity with the wrongdoers because [the latter] are broken-hearted and unable to withstand the prolonged deferral.
To the male the equivalent of the portion of two females: If the matter were to be by strict measuring, the female would be more worthy in being preferred because of her weakness and her inability to move about freely, but His decree (s) does not require justification (ghayr al-muʿallal).
[4:11 cont'd] Your parents and children - you know not which of them is nearer in benefit to you, a prescription from God; surely God is ever Knowing, Wise.
Children benefit you from their service and parents by their compassion, the parents in the state of your weakness in the beginning of your life and the children in the state of your weakness at the end of your life.