Assalaamu alaykum. Please calculate the inheritance according to the following information:
- Does the deceased have male relatives who are entitled to inherit: (A son) Number 3
- Does the deceased have female relatives who are entitled to inherit: (A daughter) Number 3 (A wife) Number 1
- The will which the deceased left behind and that is related to his inheritance is: The house in which I live will be given to my children from my second marriage. I have already given the children from my first marriage their share.
- Additional information: Details: The deceased had a wife with whom he had four children (three sons and a daughter). This wife then passed away. He then married another woman and had two more daughters. At the time of the second marriage, he had told his sons (from the first marriage) that they would have no share in anything that he would have from then on. Everything from then onwards would be for the second wife and children. The sons were happy with this arrangement as they were given land and money. When the deceased died, his house was transferred onto the second wife's name as per British law. Nothing was distributed. Now the second wife has also passed away. Now everyone wants an Islamic resolution. They know that the house should be distributed to all of the deceased's children.

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

When a man passes away leaving a wife, three sons, and three daughters, and there are no other heirs entitled to inherit, the estate should be divided as follows:

The wife gets one eighth as a fixed share due to the existence of children entitled to inherit; Allah, The Exalted, says (what means): {But if you leave a child, then for them (i.e. the wives) is an eighth of what you leave, after any bequest you (may have) made or debt.}[Quran 4:12]

The remainder should be divided among the sons and daughters by Ta’seeb (by virtue of having a paternal relation with the deceased and not having an allotted share, so they get what is left after the allotted shares have been distributed); the male gets twice the share of the female. Allah, The Exalted, says (what means): {Allah instructs you concerning your children (i.e. their portions of inheritance): for the male, what is equal to the share of two females.} [Quran 4:11]

Hence, the estate should be divided into seventy-two shares; the wife gets one eighth (9 shares), each son gets 14 shares, and each daughter gets 7 shares.

As for the will that he left, then his will in favor of his children from the second wife that they inherit his house or other properties apart from his children from the first wife considered a will in favor of an heir. The Prophet, sallallaahu ‘alayhi wa sallam, said, “Allah has given each heir his due share of the inheritance, so no will is to be made in favor of an heir.” [At-Tirmithi and others] The version cited by Ad-Daaraqutni from Ibn ‘Abbaas reads, “...unless approved by the heirs.”

Hence, his will is not binding and cannot be executed unless it is approved by his children from the first wife; if any of them refuses to carry out this will, then he should be given his due share. If the other adult, sane, and legally competent heirs approve the will, it can be executed regarding their shares, and their consent to this constitutes giving up their legitimate right in the house. If any of the heirs gives their consent to the will while below the age of distinction or while insane or legally incompetent, then their consent is not taken into consideration and their due share of the house should be saved for them.

The fact that this man gave his children from the first wife property during his lifetime makes it a gift (Hibah) and not inheritance. If he had given them this gift before marrying the second wife and having children with her, as may be understood from the question, then there is no harm in that and he was not obliged to give all his children equally, because he had no other children yet, but if he gave them this gift after his other children were born, he should have given his other children equal gifts as well in compliance with the command to treat one's children equally in terms of gift-giving. The Prophet, sallallaahu ‘alayhi wa sallam, said, “Fear Allah and maintain equality among your children.” [Al-Bukhaari and Muslim]

If he passed away before correcting this mistake (taking back the gift or giving the rest of his children equal gifts), the gift given to his children from the first wife is valid and binding according to the majority of the scholars. Some scholars, though, held that it becomes invalid and that the child who was favored with a gift is obliged to return it. Shaykhul-Islam Ibn Taymiyyah said, “It is incumbent on him (the favored child) to return the gift in his lifetime as the Prophet, sallallaahu ‘alayhi wa sallam, commanded. If he passed away before he gives back the gift, it must be returned after his death (added to the estate).”

Allah knows best.