Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: The Prophet (peace and blessings be upon him) sent one of his Companions to a Jewish man to kill him. He said: O Messenger of Allah! Permit me to say something. He (peace and blessings be upon him) said: "Say whatever comes to you, for war is deception."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11748