And to Thamûd (We sent) their brother Sâlih. He said, `O my people! worship Allâh, you have no other god than Him. A clear proof has already come to you from your Lord. Here is a she-camel (let loose for the cause) of Allâh, a sign for you. Let her alone to pasture in Allâh's land and do her no harm or a woeful punishment shall overtake you.