Abu Dawud Book 2, Hadith Number 1437.
Chapter : On reciting the supplication in prayer.
Narated By Abu Hurairah : The Apostle of Allah (PBUH) recited the supplication in the night prayer for a month. He said (in his supplication): O Allah, rescue al-Walid b. al-Walid; rescue Salamah b. Hisham, rescue the weak believers; O Allah, trample severely on Mudar; O Allah, cause them a famine like that of Joseph. Abu Hurairah said: One morning the Apostle of Allah (PBUH) did not make supplication for them. So I told him about it. He said: You do not see that they have come (back).