A man is married but does not have any children. He has a full sister and a nephew and a niece from a deceased full brother. He wishes to distribute his wealth during his lifetime among his wife and his dead brother's children through a sale contract.
Please note that his sister consents to this arrangement. Is this distribution permissible? How is a person's estate distributed after his death according to Islamic law?

It is permissible for a person to dispose of his property if:
- He is an adult.
- He is sane.
- It is his decision and he is not coerced into disposing of his property.
- His dispositions are not suspended.
- He does not make this decision during his death illness.

A person is entitled to make lawful dispositions during his lifetime in any way he wishes and according to what he sees fit. A person's dispositions before his death are considered valid and legal contracts; they are executable whether they take the form of a gift, an assignment, a sale or otherwise. Any property disposed of in any of these means is not included in the estate but is the exclusive right of the person in whose name it is written. No one else has a share in it nor is entitled to ask for any of it.

Some of the recipients who are also heirs may be allotted more in current dispositions than others due to reasons recognized by Islamic law such as:

- To fulfill a need.
- An illness.
- An affliction.
- Many children.
- To secure the future of young ones.
- To reward someone for a good act.
- Out of love.
- To assist with educational or marriage expenses and so forth.

Preferring a person to another for any of the above reasons does not render a person unjust. The preference reportedly practiced by some of the Prophet's Companions towards some of their heirs has been attributed to the above causes. It has been reported that Abu Bakr, 'A`isha and others preferred some of their heirs to others. This also sheds light on the majority of scholars' recommendation and not obligation of equitable gifting to one's children.

The ruling

Based on this, it is permissible for the man mentioned in question to distribute his wealth in the manner described and he will not be blameworthy. If, after his death, the people mentioned in the question survive him, the estate is divided as follows:

-The wife receives a quarter of the estate as an obligatory share due to the absence of a descending offspring or anyone to eliminate her share.

- His full sister receives half of the estate as an obligatory share due to the absence of another full sister, the absence of a universal heir (one who takes the remaining estate, if any, after heirs deserving obligatory shares take them) or anyone to prevent her share in the estate.

-The nephew receives the rest of the estate as a universal heir after deducting the wife's and sister's shares due to the absence of another heir deserving an obligatory share and the absence of a closer universal heir.

-The niece does not inherit anything because she is an extended family member whose shares are waived due to the existence of heirs deserving obligatory and universal heirs.
Allah the Almighty knows best.