The Prophet ﷺ was vigilant one night and when he reached Medina, he said, "Would that a pious man from my companions guard me tonight!" Suddenly we heard the clatter of arms. He said, "Who is that? " He (The new comer) replied, " I am Saʿd bin Abi Waqqas and have come to guard you." So, the Prophet ﷺ slept (that night).
سَمِعْتُ عَائِشَةَ ؓ تَقُولُ كَانَ النَّبِيُّ ﷺ سَهِرَ فَلَمَّا قَدِمَ الْمَدِينَةَ قَالَ لَيْتَ رَجُلاً مِنْ أَصْحَابِي صَالِحًا يَحْرُسُنِي اللَّيْلَةَ إِذْ سَمِعْنَا صَوْتَ سِلاَحٍ فَقَالَ مَنْ هَذَا فَقَالَ أَنَا سَعْدُ بْنُ أَبِي وَقَّاصٍ جِئْتُ لأَحْرُسَكَ وَنَامَ النَّبِيُّ ﷺ