IDIOMS

hold one's horses

(idiomatic) To be patient; to wait.

Example: 1921, Booth Tarkington, Alice Adams, ch. 24:
  "I'm going to tell you, ain't I?" he said, gruffly. "Just hold your horses a minute, please."
2007, "Force is last resort in Iranian crisis," forbes.com/Thomson Financial News, 17 Sep. (retrieved 5 Oct. 2008):
  "I would ask everybody to hold their horses until we go through the process," ElBaradei said.