keep watch over
keep (close) watch over (someone or something)
To guard, protect, or ensure the welfare of someone or something, often through close observation. I felt better sending the kids to camp when I knew Mrs. James would be there to keep close watch over them. I can't help but feeling that I had an angel keeping watch over me that day.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
keep watch over someone or something
to supervise someone or something; to take care of someone or something. Please keep watch over the project. Will you keep watch over Timmy for a minute?
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.