The Prophet ﷺ said, "War is deception."
قال النبي ﷺ: الحرب خدعة.
No references are available.
Bukhari related it in the Book of Jihad (3030), and Muslim in the Book of Jihad and Expeditions (1739:17), via the route of Sufyan bin Uyayna, from Amr (he is Ibn Dinar), that he heard Jabir say, then he related it.