The Almighty God decrees in the Qur’an about inheritance:
“When death comes to one of you, and he/she (the deceased) leaves any properties behind, it is prescribed as a duty for those among you who are mindful of God to divide it among the parents and closest relatives according to known terms (of division). The sin is upon those who change the rates of the division after hearing this. God is all-listening, all-knowing. If the person who distributes (the inheritance) has fears about being biased towards some of the heirs or falling into error, and he/she thus reconciles the heirs, it is not considered as an error on behalf of him/her. Surely, God is forgiving and beneficent.” (al-Baqarah 2:180-182)
As we see above, the shares of inheritance are determined in the Qur’an, and it is a sin to change them. The shares are written in the verses below.
Dividing the inheritance is not the duty of heirs but of mindful Muslims:
“God charges you with a duty concerning the children of the deceased:
(That is) The share of a male is equal to the shares of two females. (In case there is no male behind and) If there are (two or) more than two females behind, two-third of what is left behind is theirs. If there is only one female, half of it is hers. If the deceased has a child, then the share of each parent is one-sixth of what is left. If the deceased does not have a child and the heirs are only the parents of the deceased, then one-third of it is his/her mother’s (the rest is his/her father’s). If the deceased has brothers and sisters (of one father), then his/her mother’s share is one-sixth of it. (In all cases) The distribution comes after (firstly) fulfilling the assignment of the deceased and (secondly) paying off the debts. As for your parents and children, you can not know which of them is more beneficially closer to you. (Hence) It is explicitly prescribed by God. God knows everything, and God judges correctly.” (al-Nisa 4:11-14)
Any Muslim who is in awe of God must obey the rulings mentioned in these verses regarding inheritance. Any written will which would violate the shares mentioned in verses would be null and void. Even extra-valuable gifts that are given during the lifetime of the parent might be questionable. We can learn this from the incident mentioned in the fatwa below:
For further information, please read other inheritance-related fatwas below:
 The word translated as “properties” is “khayr = خير”. It is highly important that the word “khayr”, which means “(something) good, beneficent, advantageous”, is used to refer to that which is left behind. It points out that only good things can be left to the heirs according to Islamic laws. If the deceased leaves both wealth and debt behind, the debt is first paid from the wealth. Then, the remaining wealth is shared among the heirs. If the deceased does not leave any wealth but debt only, the heirs are not responsible for paying off the debt. If they volunteer to pay, it will be a good deed of them, both for themselves and for the deceased.
 “Parents and the closest relatives” mentioned in the verse are the heirs listed in chapter an-Nisa, verses 4:11,12,176. The right of heirship arises either by blood kinship or by a bond of marriage. Although husband and wife are not blood relatives, they become heirs of one another by the bond of marriage. In verse 4:12, shares to spouses from the inheritance are clearly stated, and it is decreed that the shares may only vary if the legator is childless. It is understood by the verses that spouses shall be the first to take their shares from the inheritance and the rest of the inheritance will be divided among the blood relatives according to the shares stated in related verses. Indeed, God draws the attention to the shares of heirs by the bond of marriage in the following verse: “To those with whom you have made a solid agreement, give them their shares” (an-Nisa 4:33).
 The expression we translate as “the duty of dividing according to known terms (of division)” is “al-wasiyyah = الْوَصِيَّةُ”. The prefix “al” is the replacement for the dropped noun “taqseem” in the actual noun phrase “wasiyyah al-taqseem”. This is the duty of dividing the wealth according to the related verses in the Quran. The expression “al-Ma’roof=” shows that the division must be performed in compliance with the known terms, that is, the shares determined in the Quran. (an-Nisa 4:11-12, 33,176)
 The root of the word “moosin = موص” is “وصي”, and it is referred to the word root “wasl = وصل” in classical dictionaries. “موصل” means “somebody (or something) that causes something to reach or arrive at another one” (Maqayis). Therefore, the word “moosin=موصٍ” has been translated as “the person who distributes” (the due shares to their owners).
 During distribution (sharing) of the inheritance, it is very difficult to determine the worth of noncash properties. In such cases, it is best to consolidate the heirs and prevent any possible enmity between them. Any effort to achieve this can not be considered as a sin or an error.
 Iltifat, meaning literally “turning to one side,” is an art in Arabic literature. One of the obvious stylistic features of this art is the use of grammatical shifts from one personal pronoun to another unexpectedly (e.g. third to second to the first person or first to second to the third person) to emphasize the expression. Sometimes, the tenses of the consecutive sentences may be changed from continuous tense to the future, or from future tense to past, etc. Sometimes, the subject of the sentence may shift from singular to plural to express the majesty (e.g. using We instead of I). These are approved as rhetorical practices in Arabic, similar to practices in some European literature. Every language has its own styles of expression. If the art of ‘iltifat’ was not considered, the sentence would be translated as: “God charges you with a duty concerning your children”. In English, it would be evaluated as if the dead person should distribute the inheritance, which is impossible. This practice of Arabic confuses the English reader. So, the sentence has been translated into English by disregarding this literal art.