From Sahih Bukhari (Hadith 7346):
Narrated Ibn `Umar:That he heard the Prophet, after raising his head from the bowing in morning prayer, saying, "O Allah, our Lord! All the praises are for you." And in the last (rak`a) he said, "O Allah! Curse so-and-so and so--and-so." And then Allah revealed:-- 'Not for you (O Muhammad) is the decision, (but for Allah), whether He turns in mercy to them or punish them, for they are indeed wrongdoers
Reference: Bukhari 7346