Random Riddle: Brothers and Sisters, I Have None

One day there was a man in a hospital bed, and there was a man sitting next to him. So, the doctor asked the man sitting next to the man in the hospital bed, he asked, who are you? The man said listen closely for I will only tell you this once. Brothers and sisters, I have none, but this man’s father is my father’s son.

Who is this man?
 

Random Riddle: Brothers and Sisters, I Have None