more than one can shake a stick at - 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 large quantity, more than one can count, as in Our town has more banks than you can shake a stick at. This idiom presumably refers to brandishing a stick as a weapon, but the precise allusion is unclear. [Colloquial; c. 1800]