Musannaf Ibn Abi Shayba 21:387

Abu Mu'awiyah narrated to us, from al-A'mash, from Raja' al-Ansari, from Abdullah ibn Shaddad, from Mu'adh ibn Jabal, who said: The Messenger of Allah (may Allah bless him and grant him peace) prayed a prayer one day and made it long. When he finished, I said: "O Messenger of Allah, you have made the prayer long today." He said: "Indeed, I prayed a prayer of hope and fear. I asked Allah for three things for my nation; He granted me two and withheld one from me. I asked Him not to empower an enemy against them from other than themselves, and He granted it to me. I asked Him not to destroy them by drowning, and He granted it to me. And I asked Him not to make their violence among themselves, and He withheld it from me."