(388) بَابُ التَّمَنِّي
'A'isha said, "The Prophet, may Allah bless him and grant him peace,was sleepless one night and said, 'Would that a man of righteous actionamong my Companions would come and guard me tonight!' Then he heard thesound of weapons. He asked, 'Who is it?' 'Sa'd,' came the answer. Sa'dsaid, 'Messenger of Allah, I have come to guard you.' The Messenger ofAllah, may Allah bless him and grant him peace, slept and we heard himsnore."
Reference: Al-Adab Al-Mufrad 878
In-book reference: Book 37, Hadith 4
English translation: Book 37, Hadith 878