That is enough, that will suffice, as in Please don't give me more peas; that will do, or That will do, children! There's to be no running near the pool. [Late 1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.