(Those are they) who said: Surely Allah has enjoined us that we should not believe in any messenger until he brings us an offering which the fire consumes. Say: Indeed, there came to you messengers before me with clear arguments and with that which you demand; why then did you kill them if you are truthful?

And to Samood (We sent) their brother Salih. He said: O my people! serve Allah, you have no god other than Him; clear proof indeed has come to you from your Lord; this is (as) Allah's she-camel for you-- a sign, therefore leave her alone to pasture on Allah's earth, and do not touch her with any harm, otherwise painful chastisement will overtake you.