I think it comes frm the horse races. The announcer person would tell them to hold their horses until everyone was ready and then he would let them go.
Hold your horses means wait, hold on. It is normally used when someone is about to do something rash or with undue haste.For more information on the history of the idiom see the link below.
The idiom "hold your horses" means to not rush into something too quickly, or to wait. It's origins date all the way back to ancient Greece. The first documented usage appears in Homer's Iliad.
"Hold your horses" is an example of an idiom, which is a phrase that has a figurative meaning different from its literal meaning. In this case, the phrase is used to tell someone to be patient or wait. The origin of this idiom can be traced back to horse riding, where holding one's horses meant to keep them still and under control.
Shakespear Play
confucius...
horses originated from Spain. When the Columbus had come from there.
what is origin of the idioum race against the clock
This is not an idiom that I have ever heard. Perhaps you mean an arm AND a leg, which is an exaggerated way of saying something is really expensive.
The popular idiom "hold the fort" or "hold down the fort" means to watch, manage, or protect an area while the speaker making the request is away.
They originate in The Netherlands.
To hope for the best
Where does eating horses originate from? France - They ate Napoleons Calvary