What is the origin of the idiom "hold your horses" and when to use it?

The origin of the idiom "hold your horses" can be traced back to horse riding and horsemanship practices. In the past, horses were commonly used for transportation and various tasks, requiring riders to have control over their horses' movements. To slow down or stop a horse, riders would pull on the reins, physically "holding" the horse back. It is often used when someone is acting hastily, impulsively, or without considering the full situation.