It was narrated that Abu Salih, the freed slace of 'Uthman, said: "uthman bin 'Affan said: “I heard the Messenger of Allah (ﷺ) say: A day in the cause of Allah is better than a thousand days doing anything else”"
HasanDaifSahihBook 25 · Hadith 86
سنن النسائي
It was narrated that Abu Salih, the freed slace of 'Uthman, said: "uthman bin 'Affan said: “I heard the Messenger of Allah (ﷺ) say: A day in the cause of Allah is better than a thousand days doing anything else”"