out of property that is liable to zakat. Likewise, if someone vows to give in charity something belonging to a category on which zakat is due, or if he vows to donate everything he owns, he must give the whole of it away. He is, however, instructed: “Keep back from it what you and your family need for maintenance until you earn another income; once you have earned something, give in charity an amount equal to what you had reserved for yourself.”