(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 certainly they had made a covenant with Allah before, that) they would not turn (their) backs; and Allah's covenant shall be inquired of.