18:24 Now David was sitting between the inner and outer gates, 1 and the watchman went up to the roof over the gate at the wall. When he looked, he saw a man running by himself.
Yehezkiel 33:2
33:2 “Son of man, speak to your people, 2 and say to them, ‘Suppose I bring a sword against the land, and the people of the land take one man from their borders and make him their watchman.