What prayer did the Prophet Muhammad (saw) teach Abu Bakr As-Siddiq to invoke Allah (swt) during his prayer?
 Narrated `Abdullah bin `Amr:                     Abu Bakr As-Siddiq said to the Prophet, "Teach me an invocation with which I may invoke (Allah) in my prayer." The Prophet said, "Say: Allahumma inni zalamtu nafsi zulman kathiran wala yaghfirudhdhunuba illa anta, Faghfirli maghfiratan min indika war-hamni, innaka antalGhafur-Rahim."