Trials and Fierce Battles (Kitab Al-Fitan Wa Al-Malahim)
Dawud :: Book 35 : Hadith 4250
Narrated Al-Miqdad ibn al-Aswad:
I swear by Allah, I heard the Apostle of Allah (peace_be_upon_him) say: The happy man is he who avoids dissensions: happy is the man who avoids dissensions; happy is the man who avoids dissensions: but how fine is the man who is afflicted and shows endurance.