A father may take whatever he needs from his son’s wealth, so long as that will not harm the son.
That is because of the report narrated by Ibn Maajah (2291) and Ibn Hibbaan in his Saheeh from the hadeeth of Jaabir, and by Ahmad (6902) from the hadeeth of ‘Abd-Allaah ibn ‘Amr (may Allaah be pleased with him), according to which a man said: O Messenger of Allaah, I have wealth and a son, and my father wants to take all my wealth. He said, “You and your wealth belong to your father.” This hadeeth was classed as saheeh by al-Albaani in Saheeh Ibn Maajah.
This taking is subject to conditions that were stipulated by the fuqaha’. Ibn Qudaamah (may Allaah be pleased with him) said: The father may take from his son’s wealth whatever he wants, and it becomes his, whethere the father needs what he takes or does not need it, whether the son is a child or an adult, subject to two conditions:
1-That he does not treat the son unfairly or harm him, and he does not take anything that his son needs.
2-That he does not take his son’s wealth and give it to another son. This was stated by Ahmad, because it is forbidden to single out one of his sons for giving from his own wealth, so it is more forbidden to single out one of his sons for giving from another son’s wealth. It was narrated that Masrooq gave his daughter in marriage for ten thousand, then he took it and spent it for the sake of Allaah, and he said to the husband: Provide your wife’s trousseau.
Abu Haneefah, Maalik and al-Shaafa’i said: He does not have the right to take from his son’s wealth anything but what he needs, because the Prophet (peace and blessings of Allaah be upon him) said: “Your blood and your wealth are scared to you, as sacred as this day of yours in this month of yours.” Agreed upon. End quote from al-Mughni (5/395).
There is a report which supports the view of the majority, that it is conditional upon the father’s need. Al-Haakim (2/284) and al-Bayhaqi (7/480) narrated that ‘Aa’ishah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Your children are a gift from Allaah to you, ‘He bestows female (offspring) upon whom He wills, and bestows male (offspring) upon whom He wills’ [al-Shoora 42:49]. They and their wealth are yours if you need it.” This hadeeth was classed as saheeh by Shaykh al-Albaani in al-Silsilah al-Saheehah (2564).
If the father needs money, he may take from his son’s wealth, and spend it on himself and his dependents, so long as that will not harm the son, and he should not take something that the son needs, like his car that he drives and so on. See also question no. 9594.
Smoking narghileh pipes is haraam, and the money that is earned from that is also haraam, but if there are things in the café that it is permissible to eat or drink, such as tea, coffee and so on, then the money that your brother earns from the café is regarded as mixed wealth, which includes both halaal and haraam. If that is the case, it is permissible for others to eat from it, if they interact with its owner by buying, selling, accepting gifts and so on, although it is better to refrain from dealing with him and taking his wealth. But as your father needs this money, there is no sin on him if he takes from him, but he should also advise his son to fear Allaah, may He be exalted, and stop dealing in haraam things.
Al-Dasooqi (may Allaah have mercy on him) said: If most of a person’s wealth is halaal and a little of it is haraam, then it is permissible to deal with him, lend him money or borrow from him, and eat from his wealth. But if most of his wealth is haraam and a little of it is halaal, then Ibn al-Qaasim is of the view that it is makrooh to deal with him, lend him money or borrow from him, and eat from his wealth, and this is the correct view. But if all his wealth is haraam, then it is not allowed to deal with him and lend him money or borrow from him, or enter into any other financial transactions with him. End quote from Haashiyat al-Dasooqi (3/277). See also question no. 45018.
And Allaah knows best.