Ruling on the grandfather showing preference to some of his grandchildren in gift giving
Question

                My father distributed his property between me and my brother and my sister in accordance with the shar‘i rules, and he also gave some of his property to my sister’s son (one of his six grandchildren). Is it permissible for him to single out one of his grandchildren to give him these things, to the exclusion of the others?
Praise be to Allah.
    
    Firstly: 

    
    It is permissible for a person to divide his wealth among his children, on 
    condition that he treat them equitably, but it is preferable for him not to 
    do that. 

    
    It says in al-Insaaf (7/142): It is not makrooh for one who is still 
    living to divide his wealth among his children, according to the correct 
    opinion. It was narrated that he [i.e., Imam Ahmad, according to another 
    view that it is makrooh] said in ar-Ri‘aayah al-Kubra: It is makrooh 
    for him to divide his wealth among his heirs when he is still alive if there 
    is a possibility that more children may be born to him. End quote. 

    
    In Fataawa al-Lajnah ad-Daa’imah (16/463) it says: We advise your 
    father not to share out his wealth during his lifetime, because perhaps he 
    may need it after that. End quote. 

    
    But if he does go ahead and share out his wealth among his children, then 
    what he must do is treat them equitably and give each male double the share 
    of each female. 

    
    Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said in al-Ikhtiyaaraat 
    (p. 184): It is obligatory to be equitable by giving to one’s children in 
    accordance with their shares of inheritance. This is the view of Ahmad. End 
    quote. 

    
    It says in Fataawa al-Lajnah ad-Daa’imah (16/197): If your father 
    wants to divide his wealth, or some of his wealth, among his children, then 
    he must share it among the males and females in accordance with the shares 
    of inheritance prescribed in Islam, with each male getting the share of two 
    females. End quote. 

    
    Secondly: 

    
    Once it is established that it is obligatory for the father to be equitable 
    in giving, then does this ruling also apply to the grandfather; in other 
    words, is it obligatory for the grandfather to be equitable in giving to his 
    grandchildren, or is that equity not required in his case? 

    
    The view of the majority of scholars is that in this case it is mustahabb 
    (encouraged), but it is not obligatory. 

    
    Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: If someone were to 
    ask: does that include the grandfather, i.e., if he has grandchildren, does 
    he have to treat them equitably (in terms of giving gifts)? 

    
    The answer is: what appears to be the case is that it is not obligatory, 
    because the strength of the connection between father and child is stronger 
    than that between grandfather and grandchildren. But if there is the fear 
    that ties of kinship may be severed (as a result of not being equitable), 
    then he should take care to give in secret to those to whom he to whom he 
    does give gifts.

    
    End quote from ash-Sharh al-Mumti‘, 11/84 

    
    Based on that, there is nothing wrong with a grandfather singling out one of 
    his grandchildren to give a gift to, to the exclusion of the others. 

    
    However, it would have been better and preferable to be equitable in giving 
    to grandchildren, so as to avoid any problems. 

    
    That is on condition that giving to his grandson is not a trick to increase 
    the share of one of his children. Please see the answer to question no.
    153385 

    
    And Allah knows best.