Comprehensive Chapter on Bequests
A Muslim should not let two nights pass without having a written will in his possession, provided he owns something over which a bequest may be made and leaves behind any wealth. Although this is not strictly obligatory, it is an act of prudence and preparedness for the suddenness of death.
A testament concerning outstanding debts is obligatory for anyone who owes money that is not supported by documented evidence.
Whoever draws up a will while in sound health or during illness may revoke it whenever he wishes. He may not, however, revoke the emancipation of a mudabbar (a slave whose freedom is deferred until the owner’s death), as explained earlier in the Book of the Mudabbar.
If a person, while ill or on a journey, makes a will and stipulates that it is to take effect only if he dies on that journey or from that illness, and he entrusts the document to someone else, the will is valid. Should he return safely from his journey while the will remains with that custodian, and he neither reclaims it nor replaces it with another, it remains perpetually binding. By contrast, if the document was retained in his own possession, it is not to be executed and no action is taken on the basis of it.