Should he build a house or give the money to his father to get married?
Question

                Should I give my father what he needs of my wealth – if he asks for it – when I want to build a house and my father wants to get married? I am renting a house and I could continue renting, but I really want a house of my own. Should I give priority to building my own house or do I have to give the
money to my father so he can get married?
Praise be to Allah.We put this question to Shaykh Muhammad ibn Saalih
    al-‘Uthaymeen, may Allaah preserve him, who answered as follows:
He has to give his father what he needs to get married, especially if
    his father is in great need of getting married.
Question: if the father wanted to build a house and asked his son for
    the money, should he give priority to his own house or his father’s house?
Answer: he should give priority to his own house over his father’s
    house.
And Allaah knows best.