al-Fard originally meant to cut a hard thing and to detach...
al-Fard originally meant to cut a hard thing and to detach its parts from one another; that is why it is used for obligatory rules, because to follow and obey it is "determined" without any doubt; "a decreed share" means a determined and fixed portion or ratio. The verse ordains a comprehensive law and legislates a new system, which was unfamiliar to the people. The people had never known any system similar to this inheritance law, as ordained in Islam.
Traditionally they used to deprive many heirs of inheritance, and it had become a second nature to them; so much so that if anything was said against it, the minds were agitated and feelings hurt. Islam paved the way for this new system, first by strengthening the "love in Allah" and giving preference to religion among the believers. Thus it established "brotherhood" between the believers and then made one "brother" inherit the other.
This wiped out the previous succession rules, and the believers abandoned the old pride and prejudice. When the religion became strong and could stand on its feet, this final system of inheritance between the relatives was introduced - at a time when they were enough believers to accept this law with open arms. The above discussion shows that these verse aims at clear description, and removal of all possible misunderstandings, by giving a fundamental and comprehensive basis of the law.
Thus it says: "Men shall have a share of what the parents and the near relatives leave." The rule is general and unrestricted; it is not qualified by any condition, attribute or other such things. Likewise the subject, i.e., "men", is general and not qualified in any way; therefore the minors shall inherit like the adults.
Then it says: "and women shall have a share of what the parents and the near relatives leave." Like the preceding sentence it is a general statement, without any shade of restriction; thus it covers all women without any qualification or condition. The clause, "of what the parents and the near relatives leave" has been repeated, although it could be replaced by a pronoun, the reason is to make the topic as clear as possible.
It is followed by the clause, "whether there is little or much of it"; it makes the matter even more clear, and shows that there is no room for any indulgence or negligence in this matter thinking that the deceased's estate was very small or the value negligible.