(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?

(This is a declaration of) immunity by Allah and His Messenger towards those of the idolaters with whom you made an agreement.

How can there be an agreement for the idolaters with Allah and with His Messenger; except those with whom you made an agreement at the Sacred Mosque? So as long as they are true to you, be true to them; surely Allah loves those who are careful (of their duty).