Bible Verses About Watchmen: Reported the approach of all strangers

Now David was sitting between the two gates: and the watchman went up to the roof of the gate unto the wall, and lifted up his eyes, and looked, and, behold, a man running alone.

And the watchman cried, and told the king. And the king said, If he be alone, there is tidings in his mouth. And he came apace, and drew near.

And the watchman saw another man running; and the watchman called unto the porter, and said, Behold, another man running alone. And the king said, He also bringeth tidings.

And the watchman said, I think the running of the foremost is like the running of Ahimaaz the son of Zadok. And the king said, He is a good man, and cometh with good tidings.

So there went one on horseback to meet him, and said, Thus saith the king, Is it peace? And Jehu said, What hast thou to do with peace? turn thee behind me. And the watchman told, saying, The messenger came to them, but he cometh not back.

Then he sent out a second on horseback, who came to them, and said, Thus saith the king, Is it peace? And Jehu answered, What hast thou to do with peace? turn thee behind me.

And the watchman told, saying, He came even unto them, and cometh not back: and the driving is like the driving of Jehu the son of Nimshi; for he driveth furiously.

For thus hath the Lord said unto me, Go, set a watchman; let him declare what he seeth:

and when he seeth a troop, horsemen in pairs, a troop of asses, a troop of camels, he shall hearken diligently with much heed.

and, behold, here cometh a troop of men, horsemen in pairs. And he answered and said, Fallen, fallen is Babylon; and all the graven images of her gods are broken unto the ground.