Because of its many narrations that strengthen each other, this Hadeeth is not weak. And it means that if a man has wealth, his father may be free with that wealth, taking what he wants from it, but under conditions:
1) By taking his son's money, a father may not bring harm to him. For example, it is not permitted for a father to take a coat that his son uses for protection from the cold or to take his food that he uses to ward off hunger.
2) That wealth must not be from things that the son needs. For example, if the son has a female slave, the father may not take her, since the son needs her. If the son has a car that he uses to get from one place to another and if he doesn't have money to buy a replacement, his father may not take it from him.
3) The father may not take wealth from one child to give it to another of his children, because this will lead to enmity between the children and because doing so involves favouritism for some of one's children over the others. If, however, one of his children is needy, the father is not only permitted to give him money (without giving to the others), but he must give to him.
In any case, this Hadeeth is a binding proof, one that the scholars accept and implement, but as I said, with conditions. When he takes wealth from his son, a father is not permitted to harm him, is not permitted to take what that son needs, and is not permitted to take from that son to give to another son. And Allaah Almighty knows best.