Book 25, Hadith 85

It was narrated from Zurah bin Ma'bad:"Abu Salih, the freed slave of 'Uthman, said: 'I heard 'Uthman bin 'Affan say: I heard the Messenger of Allah (ﷺ) say: Ribat (guarding the frontier) for one day in the cause of Allah is better in rank than a thousand days spent within the residence