It wasnarrated that 'Abdullah bin Zubair said:
"Uthman bin 'Affanaddressed the people and said: 'O people! I heard a Hadith from theMessenger of Allah (ﷺ) and nothing kept me from narrating it to youexcept for the fact that I did not want to lose you and yourcompanionship. So it is up to you. I heard the Messenger of Allah(ﷺ) saying: "Whoever spends a night guarding the frontier in thecause of Allah, it will be like a thousand nights spent in fastingandprayer." (FR)
English reference (FR): Vol. 4, Book 24, Hadith 2766 (FR)
Arabic reference (FR): Book 24, Hadith 2871 (FR)