One of the most important principles of Islam is that all things belong to Allah, and that wealth is therefore held by human beings in trust. The word zakat means both 'purification' and 'growth'. Our possessions are purified by setting aside a proportion for those in need, and, like the pruning of plants, this cutting back balances and encourages new growth.

Each Muslim calculates his or her own zakat individually. For most purposes this involves the payment each year of two and a half percent of one's capital.

A pious person may also give as much as he or she pleases as sadaqa, and does so preferably in secret. Although this word can be translated as 'voluntary charity' it has a wider meaning. The Prophet peace be upon him said 'even meeting your brother with a cheerful face is charity.'

The Prophet said peace be upon him: 'Charity is a necessity for every Muslim.' He was asked: 'What if a person has nothing?' The Prophet peace be upon him replied: 'He should work with his own hands for his benefit and then give something out of such earnings in charity.' The Companions asked: 'What if he is not able to work?' The Prophet peace be upon him said: 'He should help poor and needy persons.' The Companions further asked 'What if he cannot do even that?' The Prophet peace be upon him said 'He should urge others to do good.' The Companions said 'What if he lacks that also?' The Prophet peace be upon him said 'He should check himself from doing evil. That is also charity.'