and they swear by allah with the strongest of their oaths that if a sign came to them they would most certainly believe in it. say signs are only with allah and what should make you know that when it comes they will not believe?
وأقسموا بالله جهد أيمانهم لئن جاءتهم آية ليؤمنن بها قل إنما الآيات عند الله وما يشعركم أنها إذا جاءت لا يؤمنون