Lord Allah is advising you concerning your children, a male has a portion equivalent to that of two females; if the females are more than two, then two-thirds of whatever you left is to them, if she is only one, then she has half. Both his parents, each of them has one-sixth of whatever you left if he has a son. If he has no son his father inherits it giving one-third to his mother. If he has brothers or sisters, then the mother has one-sixth after the bequests or any debt has been settled. You don’t know among them your fathers and your children who will be nearest for you in benefit, compulsory partition from Lord Allah; indeed, Allah is the All-Knowing, the Wise.
It is the responsibility of the male, whether he is husband or father to meet the expenses of the family including women and children. That is why the male is given double of the female in the inherited property. It is told in verse 4: 34 that men are the protectors and maintainers of women because of that Lord has graded some among them upon others, and due to that men are spending from his properties for women. If the deceased person leaves no children and if the father has other children from another wife, the portion of the mother is reduced from one-third to one-sixth due to the responsibility of the father to look after his children. The children get the inheritance only after the death of their father. If the son dies before the death of the father, the son’s children have no inheritance. But one-third of the property of grandfather can be made as a bequest to the grandchildren considering their financial condition.
The aim of life is to construct Paradise in this world with all the Bounties bestowed by the Lord. But only the believer who lives by seeing Lord through the Best Book Adhikr can understand all these dos and don’ts as Justice. That is why it is told in this verse: “Allah is the All-knowing, the Wise” and “You don’t know among them your fathers and children who will be more nearest for you in benefit”.
In this verse, even though bequest is mentioned before debt, the debt must be settled before bequest. The believer always prays to settle the debt and will try to settle it in his lifetime itself. Though one can amend the bequest as told in verses 2: 180-182, no excuse is allowed in the matter of debts. Lord has taught through His Messenger that even the debt of martyr for the sake of the Lord will not be ignored. Debts are the trust and responsibility between mankind, so the Impartial Lord has nothing to do with them. No prayer will be responded and no deed will be accepted without becoming a believer with Adhikr as explained in verse 2: 186. So the Arabic Quran reading Fujjar who lead aimless and heedless life in this world by hiding and rejecting Adhikr will have Hell as a penalty as explained in verses 9: 67-68. See explanation 2: 255, 269, 282-283, and 3: 7-10.