'Myrtle trees' in the Bible

"I had a vision in the night, and behold, a man riding on a red horse, and he stood among the myrtle trees that were in a ravine; and behind him there were red, brown, and white horses.

The man who stood among the myrtle trees answered, "They are the ones Yahweh has sent to go back and forth through the earth."

They reported to the angel of Yahweh who stood among the myrtle trees, and said, "We have walked back and forth through the earth, and behold, all the earth is at rest and in peace."