Jihad: The forgotten obligation
37: To Take a Pledge of Allegiance Upon Death And Not to Flee from the Battlefield
Narrated Yazid ibn Ubayd: Salama (ra) said, "I gave the pledge of allegiance (al Ridwan) to Allah's Apostle (saw) and then I moved to the shade of a tree. When the number of people around the Prophet (saw) diminished, he said, "O Ibn al Aqwa! will you not give to me the pledge of allegiance?" I answered, "O Allah's Apostle! I have already given you the pledge of allegiance." He said, "Do it again." So I gave the pledge of allegiance for the second time." I asked, "O Abu Muslim! for what did you give the pledge of allegiance that day?" He replied, "We gave the pledge of allegiance for death". (Sahih Bukhari, p.415, vol.1)