Unto the people of Thamud We sent Salih, one of their own brethren. He said, "O my people! Serve (or worship) Allah; you have no God but Him. There has come to you a manifest Sign from your Lord. This is Allah's she-camel, a sign (or test) unto you; so leave her to feed in Allah's land, and touch her not with evil, or there will overtake you grievous woe.