The waqf is the most important branch of the Mohammadan Law. The doctrine has been recognised and enforced in the Mussalman system from the time of introduction of Mohammadan Law. It has been originated from direct prescriptions of the Prophet. Its validity is founded on the rule laid down by the Prophet himself. Omar had acquired a piece of land in Khaibar, and went to the Prophet and sought his advice, to make the most pious use of it, whereupon the Prophet said, 'tie up the property and devote the usufruct to human beings, and it is not to be sold or made the subject of gift or inheritance; devote its produce to your children, your kindred, and the poor in the way of God'. Accordingly Omar dedicated the property. The law of waqf has its origin with the Prophet himself, who, besides having prescribed the rule to Omar declared that all human actions end with the life of the individual, except such benefactions as are perpetual in their character; and that, in accordance with these principles, trusts or dedications were frequent in the life time of the Prophet and the early centuries of Islam. Thus the waqf is interwoven with the entire religious life and social economy of the Mussalmans.