Narrated Yazid bin Abi Ubaid: I said to Salama bin Al-Akwa, "For what did you give the Pledge of allegiance to Allah's Apostle on the day of AlHudaibiya?" He replied, "For death (in the Cause of Islam.)."
— Sahih Bukhari, Volume 5, Book 59: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi), Hadith #487