The creator Lord Brahma asked Lord Vishnu to preserve the world. Lord Vishnu agreed provided he be given a holy place from where he could perform his duty. Lord Brahma picked up a handful of Kusha grass and flung it towards Earth. Kusha grass landed at Ujjain, and Lord Vishnu performed his duty sitting on Kusha grass. Ujjain thus came to be known as Kusha sthali.