In Surat (An-Nisaa), there are verses that define the how the inheritance should be divided and imposed a clear share for the parents and the children as well. However, the will may specify the one-third of the wealth only as  stated in the Hadith which was narrated by Sa’d bin Abi Waqqass:

“The Prophet (saws) visited me at Mecca while I was ill. I said (to him), “I have property; May I bequeath all my property in Allah’s Cause?” He said, “No.” I said, “Half of it?” He said, “No.” I said, “One third of it?” He said, “One-third (is alright), yet it is still too much”.

The Prophet (saws)‏ stated that the will should not exceed one-third of the inheritance and it is not allowed for the parents and the children to have share in the will according to the Prophet (saws)‏ saying:

“… no bequest must be made to an heir”.[1]

Thereof, those who have shares in the inheritance have no right in the will. However, the ones who deserve to be part of the will are the relatives according to this verse, Allah (swt) says:

 {إِذَا حَضَرَ الْقِسْمَةَ أُولُو الْقُرْبَىٰ وَالْيَتَامَىٰ وَالْمَسَاكِينُ فَارْزُقُوهُم مِّنْهُ وَقُولُوا لَهُمْ قَوْلًا مَّعْرُوفًا }

(And when [other] relatives and orphans and the needy are present at the [time of] division, then provide for them [something] out of the estate and speak to them words of appropriate kindness.)  (An-Nisaa: 8)

(… جَنَفًا … ) (…error…): What does “error” refer to?  It means moving away from the right path and the justice. From this meaning the Arabic word is used to indicate the spine scoliosis disease, where the spine twists and curves.

(… فَأَصْلَحَ بَيْنَهُمْ … ) (…and corrects that which is between them…): meaning, he interferes for reforming.

(… فَلَا إِثْمَ عَلَيْهِ … ) (…there is no sin upon him…): If a Muslim attended a meeting in which the testator has dictated his will but he committed injustice, unfairness, inequality, or even he violated the Islamic law, in such a case, there is no sin on this Muslim if tried to correct the errors. The testator has to be advised not to exceed the one-third share and to include the relatives in the will, and to exclude the inheritors and not to violate the Islamic law.  Subsequently, the will has to be in accordance with the Islamic law and this is a very important matter; because the will is the last thing the man does in his life and he is accountable for it. Yes, the man writes the will when he is alive, but its effect will be after his death. Therefore, this will must be just and fair according to the Islamic legislations.

(إِنَّ اللَّهَ غَفُورٌ رَّحِيمٌ  … ) (Allah is Forgiving and Merciful…): These verses end with the forgiveness of Allah (swt) and His mercy, which include everything.

[1]  Sunan Ibn Majah, Book of wills, hadith No (2714)