سورة Al-Kahf ( The Cave ) - الآية 19

And similarly We awakened them so that they may enquire about each other; a speaker among them said, “How long have you stayed here?” Some among them said, “We have stayed a day or part of a day”; the others said, “Your Lord well knows how long you have stayed; therefore send one of you to the city with this silver coin – he may then check which food available there is purer, in order to bring some of it for you to eat – and he must be courteous and not inform anyone about you.”