stone's throw, a - Phrases/Idioms
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.
A very short distance, as in They live just a stone's throw from us. This metaphoric term alludes to how far one can toss a stone. [Second half of 1500s]