khums — special form of almsgiving required of Shi`a s to provide maintenance for and support the work of the descendants of the Prophet; it is the Arabic word for one - fifth. (religion-online.org)
Theologians, however, can still be moved by the question: The Lutheran Church historian Carter Lindberg, for instance, offers a strong defense of the classic Protestant understanding of almsgiving in his book Beyond Charity: Reformation Initiatives for the Poor. (firstthings.com)
Mark Elvins points out that in mediaeval times it was clear that almsgiving required compassion for the person in need as much as bodily help. (faith.org.uk)