'Myrtles' in the Bible

I have seen by night, and lo, one riding on a red horse, and he is standing between the myrtles that are in the shade, and behind him are horses, red, bay, and white.

And the one who is standing between the myrtles doth answer and say, 'These are they whom Jehovah hath sent to walk up and down in the land.'

And they answer the messenger of Jehovah who is standing between the myrtles, and say, 'We have walked up and down in the land, and lo, all the land is sitting still, and at rest.'