Sayyidah Ayshah (RA) narrated: Allah’s Messenger ﷺ arrived in Madinah one night from a battle but could not sleep. So, he said, “Would that a pious man stand guard for me tonight!” While we were on tht,’we heard a rustle of weapons. He asked, ‘Who is that?” There was a reply, “Sa’d ibn Abu Waqqas.” Allah’s Messenger ﷺ asked, “What is with you?” Sad said, “I felt within myself fear for Allah’s Messenger ﷺ ?-‘ So, I came to guard him.” So, Allah’s Messenger ﷺ prayed for him. Then he went to sleep. [Ahmed 25147, Bukhari 2885, Muslim 2410] --------------------------------------------------------------------------------