The march of the army through the desert was a great ordeal. The long trek across the desert exhausted the water supplies at the disposal of the troops, and the absence of water became an acute problem. Ali sent his scouts to inquire of the tribesmen in the desert whether there were any wells or springs in the neighborhood which could supply water to the troops. The tribesmen said that there were no wells or spring in the neighborhood.
Ali had heard that some centuries ago the Israeli patriarchs had dug wells in the desert, and he hoped to be able to find out these ancient sites. The scouts who contacted the tribes in the desert were not able to get any clue of a spring or a well in the desert. One of the scouts, however, brought back with him an old Christian hermit who said that there was indeed a cistern in the neighborhood in the past, but it had gone dry. The hermit added that according to old legends, a hidden well existed somewhere in the neighborhood, and its mouth was covered with an enormous stone, but no one knew about the actual site of the legendary well. He observed that according to popular belief no one could locate the hidden well, except a prophet or the representative of a prophet.