'Myrtle trees' in the Bible

I looked by night, And lo! a man riding upon a red horse, and he was standing among the myrtle trees, in the shade; and, after him, were horses, red, bay, and white.

So the man who was standing among the myrtle-trees responded, and said, - These, are they whom Yahweh, hath sent, to go to and fro through the earth.

Then responded they to the messenger of Yahweh, who was standing among the myrtle-trees, and said, We have gone to and fro through the earth, - and lo! all the earth, resteth and is quiet.