The "sleeping man" in Saudi Arabia is likely referring to Prince Alwaleed bin Khalid bin Talal, who has been in a coma for over 15 years. He is known as the "Sleeping Prince" and is a member of the Saudi royal family.
While the term "sleeping man" might also refer to other situations, such as the prevalence of sleep-related accidents among drivers or the cultural perception of Saudis as "sleeping koalas," Prince Alwaleed bin Khalid is the most prominent and well-known individual associated with this term.