Sahih Bukhari

Narrated `Aisha: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 Sa`d bin Abi Waqqas and have come to guard you."" So, the Prophet (ﷺ) slept (that night)