'Keep Watch' in the Bible

It will be like a man who leaves his home and goes on a journey, after he has given orders to his slaves, to each his particular task, and has given orders to the watchman to keep watch.

and so He said to them, "My heart is breaking, it almost kills me! You must stay here and keep watching."

You must all keep watching and praying that you may not be exposed to temptation. Man's spirit is willing but human nature is weak."