Is it permissible for a wife to take from her husband's money without his knowledge if he does not spend on her or on the household necessities?

The wife's maintenance does not cease due to her wealth or employment, unless the husband stipulates that she spends on herself in exchange for his permission for her to work. If he does not stipulate this to her, and he permits her, then her maintenance does not cease to be his responsibility. She may take from his money, as is customary, what suffices her and her children without his knowledge, based on the saying of the Prophet, peace and blessings be upon him, to Hind bint Utbah: "Take from his money, as is customary, what suffices you and suffices your children." As for the son, if he possesses wealth, he should spend on himself from it, and his maintenance is not obligatory upon the father; thus, he should not take from the father's money in such a case.