Scholars distinguish between the small and the large amount of the husband’s property taken to be given in charity by the wife. If small, the husband’s permission is not mandatory; but if large, then the husband must be acquainted and his permission must be taken.
Dr.`Ugail Jasem An-Nashmi, professor of Islamic jurisprudence in Kuwait, states the following: It is permissible for a woman to give in charity from the property of her husband which is at her disposal at home, yet he must be acquainted and his consent is required. However, if what is given in charity is agreed upon to be insignificant, then there is no harm in giving it in charity without the husband’s permission. In this regard, it is narrated on the authority of `A’ishah (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: “If a woman gives in charity from her house meals without spoiling her husband’s property, she will get a reward for almsgiving, and her husband will also get a reward for his earnings, and the storekeeper will get a reward likewise. None of them decreases the reward of the other.”

Moreover, while delivering the Farewell Sermon (the last one delivered by the Prophet), the Prophet (peace and blessings be upon him) said: “A woman should never spend from the property of her husband without her husband’s permission.” He was asked: “Not even food, O Messenger of Allah?” Upon that, the Prophet replied: “It is the best of our property.”
This shows that the husband’s permission and consent are mandatory unless what is given in charity is so insignificant, as it can be done without the husband’s permission. This is illustrated in the Prophet’s reply to Asma’ bint Abi Bakr (may Allah be pleased with her) when she said to him: “Az-Zubair is a strict man, and sometimes an indigent begs me so I give him in charity from his (Az-Zubair’s) house property without his permission.” The Prophet (peace and blessings be upon him) replied, “Give in charity and do not withhold it, lest Allah withholds it from you.”