'Myrtle trees' in the Bible

I watched by night. And behold! a Man riding on a red horse, and He stood among the myrtle trees in the ravine. And behind Him were red, sorrel and white horses.

And the Man who stood among the myrtle trees answered and said, These are those whom Jehovah has sent to walk to and fro through the earth.

And they answered the Angel of Jehovah who stood among the myrtle trees, and said, We have walked to and fro through the earth, and behold, all the earth sits still and is at peace.