What did the Prophet Muhammad (peace be upon him) invoke Allah to do when Jarir informed him he could not sit firm on horses?
 Narrated Qais:                     Jarir bin `Abdullah said to me, "Allah's Apostle said to me, 'Won't you relieve me from Dhul- Khalasa?' Dhul-Khalasa was a house where the tribe of Khatham used to stay, and it used to be called Ka`bat-ul Yamaniya. So I proceeded with one hundred-and-fifty (men) from the tribe of Ahmas who were good cavalry. I informed the Prophet that I could not sit firm on horses, so he stroke me on the chest with his hand and I noticed his finger marks on my chest. He invoked, 'O Allah! Make him firm and a guiding and rightly-guided man." Jarir set out towards that place, dismantled and burnt it, and then sent the good news to Allah's Apostle . The messenger of Jarir said to Allah's Apostle. "O Allah's Apostle! By Him Who has sent you with the Truth, I did not come to you till it (i.e. the house) had been turned (black) like a scabby camel (covered with tar)." So the Prophet invokes Allah to Bless the horses of the men of Ahmas five times.