What was the prayer of the Prophet Muhammad (saw) when invoking Allah?
 Narrated Abi Huraira:                     The Prophet used to invoke Allah in his prayer, "O Allah! Save `Aiyash bin Abi Rabi`a and Salama bin Hisham and Al-Walid bin Al-Walid; O Allah! Save the weak among the believers; O Allah! Be hard upon the tribe of Mudar and inflict years (of famine) upon them like the (famine) years of Joseph."