Bible Verses About Towers: Watchmen posted on, in times of danger

The watchman therefore, that stood upon the tower of Jezrahel, saw the troop of Jehu coming, and said: I see a troop. And Joram said: Take a chariot, and send to meet them, and let him that goeth say: Is all well?

I will stand upon my watch, and fix my foot upon the tower: and I will watch, to see what will be said to me, and what I may answer to him that reproveth me.