Abu Salih, the freed slave of Uthman bin Affan (may Allah be pleased with him), says: I heard Uthman bin Affan (may Allah be pleased with him) saying on the pulpit: I have kept from you a hadith that I heard from the Messenger of Allah (peace and blessings be upon him); I kept it hidden out of fear that you would all leave me and go away. Then it occurred to me to narrate it, so that each person may choose what seems good to him. I heard the Messenger of Allah (peace and blessings be upon him) saying: "One day of standing guard in the path of Allah is better than a thousand days of guarding in any other place."
Imam al-Tirmidhi (may Allah have mercy on him) declared it hasan sahih.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17888