give the word
give (someone) the word
To give an order, make a request, or expressly state a desire for someone to do something or undertake some task. We're ready to begin writing the report whenever you are, so just give us the word, and we'll get going. If the President gives the word, the military could begin airstrikes as early as tomorrow morning.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
give the word
Also, say the word. Give an order, tell or show when something is to be done, as in If you want us to move out, just give the word, or When you want the car, just say the word. The first expression, dating from about 1400, originally alluded to uttering a password in response to a sentinel's challenge. The second is even older, appearing in an early translation of the biblical books of Genesis and Exodus: "And God said the word to Abraham."
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.