The father must treat his children equally when giving gifts, because of the report narrated by al-Bukhaari (2586) and Muslim (1623) from al-Nu’maan ibn Basheer, that his father took him to the Messenger of Allaah (peace and blessings of Allaah be upon him) and said: “I have given this son of mine a slave.” He said: “Have you given something similar to all of your children?” He said: No. He said: “Then take it back.”
According to a version narrated by al-Bukhaari (2587), he said: “Fear Allaah and treat your children fairly.” So he went back and took back his gift.
According to another report narrated by al-Bukhaari (2650): “Do not ask me to bear witness to falsehood.”
According to a report narrated by Muslim (1623) he said: “Would you not like them all to honour you as you want this one to?” He said: Of course. He said: “Then I will not bear witness.”
Differentiating between children in gift giving causes resentment and creates grudges, and makes disobedient children even more disobedient and rebellious.
Hence the correct view is that it is haraam and should not be done, unless it is for a legitimate shar’i reason. See question no. 22169.
Ibn Qudaamah (may Allaah have mercy on him) said: One should treat children fairly with regard to gift-giving, and not single out any of them in a way that shows preferential treatment. If he singles out one of them for a gift or he differentiates between them, then he is sinning and he has to treat them fairly by doing one of two things: either taking back that which he gave to some or by giving (something similar) to the others. End quote from al-Mughni (5/387).
The Standing Committee was also asked: My mother owns a small house that she built from scratch and I have a brother who did not take any part in that with me at all, rather he makes my mother and father very angry and has treated them badly all his life until now. Now he is living outside the home, and my mother got angry and decided to put this house in my name. I discussed the matter with her many times but she is determined to put it in my name. Now I am asking: will there be any sin on my mother if she puts the house in my name to deprive my brother of it? Will there be any sin on me if I accept that from my mother?
If the situation is as described, it is not permissible for your mother to give the house to you and not your brother, because the Prophet (peace and blessings of Allaah be upon him) said: “Fear Allaah and treat your children fairly.” And because of other hadeeth that have been narrated on this topic. If she does what is mentioned, then she will be sinning and you will be sinning, because if you accept that from her you will be a partner in the sin and transgression, and Allaah has forbidden that as He says (interpretation of the meaning):
“Help you one another in Al‑Birr and At‑Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression. And fear Allaah. Verily, Allaah is Severe in punishment”
So the gift should be returned or the second son should be given something of equal value. If you see that she is insisting on not giving him a share with you, there is nothing wrong with accepting the gift and giving your brother half of it, so that you will have discharged your duty, if there are no other children apart from you two. And Allaah is the Source of strength. May Allaah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote.
And Allaah knows best.