case in point
case in point definition by American Heritage Dictionary
noun pl. cases in pointThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A relevant illustrative example.
case in point - Phrases/Idioms
A relevant example or illustration of something, as in A case in point was the collision of a cyclist with a pedestrian crossing the designated bike path. [Mid-1700s]