Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), he says: We were at the Battle of Badr, and there was one camel for every three men. Sayyiduna Ali and Sayyiduna Abu Lubabah were the (traveling) companions of the Messenger of Allah (peace and blessings of Allah be upon him). When it was the turn of the Messenger of Allah (peace and blessings of Allah be upon him) to walk, both of them would say: O Messenger of Allah! You ride, we will walk. The Messenger of Allah (peace and blessings of Allah be upon him) would say: "You are not stronger than me in walking, nor am I in less need of reward than you."