Mulberry Tree
The mulberry-trees appear in scripture at one battle, where they serve as both a landmark and a signal in David's campaign against the Philistines in the valley of Rephaim.
The Sign in the Tops
When the Philistines come up against David a second time and spread themselves in the valley of Rephaim, David inquires of Yahweh, and the answer comes with a precise tactical instruction: "You will not go up: make a circuit behind them, and come upon them across from the mulberry-trees" (2Sa 5:23). The trees become a navigation point — David is told where to position relative to them — and then they become the signal for the attack itself: "And it will be, when you hear the sound of marching in the tops of the mulberry-trees, that then you will bestir yourself; for then Yahweh has gone out before you to strike the host of the Philistines" (2Sa 5:24). David obeys, and the result is recorded plainly: "And David did so, as Yahweh commanded him, and struck the Philistines from Geba until you come to Gezer" (2Sa 5:25).
The action of the passage rests on the trees themselves. Yahweh's going out before David is heard, not seen, and what is heard is a sound of marching — not at ground level but in the tops of the mulberry-trees.