The phrase is "hold your horses", and it means "Wait a minute! Don't rush into doing something without stopping to think first!"

"Hold your horses" is a common idiom which means to wait or to control oneself. Ex. Hold your horses, I'm coming!

It is "hold your horses". You would say this to someone to warn or discourage them from doing something which they have not properly thought about or were rushing into without considering all the risks. Son:I am going to quit university and travel around Europe! Father: Hold your horses. You are going to finish your studies before you go wandering around the world.