Can mustahabb charity be given to a non-Muslim?
Question

                If a man needs charity and he does not pray, is it permissible to give him charity?.
Praise be to Allah.
    Obligatory charity, such as zakaah or other financial 
    obligations, like expiation, vows and zakaah al-fitr, cannot be given to a 
    kaafir unless it is intended to soften their hearts (towards Islam). But 
    voluntary charity and donations may be given to non-Muslims if that will 
    serve an interest, such as if they are close relatives and so on, because 
    the Prophet  (peace and blessings of Allaah be upon him) said to Asma’ 
    bint Abi Bakr (may Allaah be pleased with her): “Uphold ties of kinship with 
    your mother” who was a kaafir woman. 

    But with regard to zakaah and obligatory charity, it is not 
    permissible to give them to a kaafir except in cases where their hearts are 
    to be softened (towards Islam), because the Prophet  (peace and 
    blessings of Allaah be upon him) said concerning zakaah: “It is to be taken 
    from their rich and given to their poor” referring to Muslims. 

    End quote.