In this way We raised them up until they asked each other. One of them said, .How long did you tarry?. They said, .A day, or part of a day. They said, .Your Lord knows best how long you tarried. So, send one of you with this silver (coin) of yours to the city and let him look around which of the eatables are the purest and let him bring you some food from there. And he must act in polite manner, and must not let anyone know about you.