What did the Prophet Muhammad (peace be upon him) sometimes pray for in a loud voice during the Fajr prayers?
 Narrated Abu Huraira:                     Whenever Allah's Apostle intended to invoke evil upon somebody or invoke good upon somebody, he used to invoke (Allah after bowing (in the prayer). Sometimes after saying, "Allah hears him who sends his praises to Him, all praise is for You, O our Lord," he would say, "O Allah. Save Al-Walid bin Al-Walid and Salama bin Hisham, and `Aiyash bin Abu Rabi`a. O Allah! Inflict Your Severe Torture on Mudar (tribe) and strike them with (famine) years like the years of Joseph." The Prophet used to say in a loud voice, and he also used to say in some of his Fajr prayers, "O Allah! Curse soand- so and so-and-so." naming some of the Arab tribes till Allah revealed:--"Not for you (O Muhammad) (but for Allah) is the decision." (3.128)