succession act

Muslim law recognises that persons may leave behind a will, but a will (unless ratified by all the heirs of the person leaving behind the will) is valid only to the extent of one-third of the deceased's property. Insofar as it is valid, it is governed by the regular laws applicable to wills in India.

The reason for restricting a person's testamentary capacity to a third is on account of what has been stated by the Prophet Himself in conversation with one of his disciples, Abu Waqqas.

Abu Waqqas was ill and very near dying and the Prophet came to see him. Abu Waqqas said to the Prophet, "O Prophet, I have much property and no heir other than my daughter. May I leave a will, bequeathing all my properties for charitable purposes?" The Prophet replied that he could not. "May I leave 2/3rd then?", he asked. The Prophet again replied that he could not. "May I leave half then?" Again the answer came in the negative. "May I leave 1/3rd then?", he persisted. And the Prophet replied, "Make a will disposing one third in that manner, for one third is a great deal." The Prophet went on to say, "Verily, it is better that you leave your heirs rich, than to leave them poor to beg."

This account is related in the book, Mischat ul Masabih. Since this rule is something the Prophet has Himself stated, it has the force of law, it being a Sunna.