What was the prayer for intercession that Prophet Muhammad (saw) reserved for his Ummah on the Day of Resurrection?
 Anas b. Malik reported:                      Verily the Apostle of Allah (may peace be upon him) said: There is for every apostle a prayer with which he prays (to Allah) for his Ummah. I have reserved my prayer for the intercession of my Ummah on the Day of Resurrection.