Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(These are the limits (imposed by) Allah) these are the legal rulings and obligations imposed by Allah. (Whoso obeyeth Allah and His messenger) regarding the division of estates, (He will make him enter Gardens beneath which) beneath its habitations and trees (rivers) rivers of wine, water, honey and milk (flow, where such will dwell for ever) dwelling forever in Paradise, never to die or leave it. (That will be the great success) the greatest salvation through entering Paradise.
Those, rulings mentioned with respect to orphans and what followed, are God’s bounds, His laws, which He has delimited for His servants, so that they may act in accordance with them and not infringe them. Whoever obeys God and His Messenger, in what He has ruled, He will admit him (yudkhilhu, or, as a shift [to the first person plural] read nudkhilhu, ‘We will admit him’) to Gardens underneath which rivers flow, abiding therein; that is the great triumph.
Warning Against Transgressing the Limits for Inheritance
Meaning, the Fara'id are Allah's set limits. This includes what Allah has alloted for the heirs, according to the degree of relation they have to the deceased, and their degree of dependency on him. Therefore, do not transgress or violate them. So Allah said;
وَمَن يُطِعِ اللَّهَ وَرَسُولَهُ
(And whosoever obeys Allah and His Messenger,) regarding the inheritance, and does not add or decrease any of these fixed shares by use of tricks and plots. Rather, he gives each his appointed share as Allah commanded, ordained and decided,
(Will be admitted to Gardens under which rivers flow (in Paradise), to abide therein, and is the great success. And whosoever disobeys Allah and His Messenger, and transgresses His (set) limits, He will cast him into the Fire, to abide therein; and he shall have a disgraceful torment.) This is because he changed what Allah has ordained and disputed with His judgment. Indeed, this is the behavior of those who do not agree with what Allah has decided and divided, and this is why Allah punishes them with humiliation in the eternal, painful torment. Imam Ahmad recorded that Abu Hurayrah said that, the Messenger of Allah said,
(A man might perform the actions of righteous people for seventy years, but when it is time to compile his will, he commits injustice. So his final work will be his worst, and he thus enters the Fire. A man might perform the deeds of evil people for seventy years, yet he is fair in his will. So his final work will be his best, and he thus enters Paradise.) Abu Hurayrah said, "Read, if you will,
تِلْكَ حُدُودُ اللَّهِ
(These are the limits (set by) Allah) until,
(a disgraceful torment.).'' In the chapter on injustice in the will, Abu Dawud recorded in his Sunan that Abu Hurayrah said that the Messenger of Allah said,
Those are God's bounds. Whoever obeys God and His Messenger He will admit him to gardens underneath which rivers flow abiding therein; that is the great triumph. His bounds ḥudūd are His commands and prohibitions and that by which His servants ʿibād show their devotion taʿabbada bihi. The root of servanthood ʿubūdiyya is preserving the bounds ḥudūd and maintaining the promises ʿuhūd. Whoever preserves His limit nothing bad or harmful will reach him. The root of every affliction is going beyond the bounds.