בראשית, פרק מ״ט, פסוק י״ז

Jacob blesses the tribe of Dan with a unique military destiny, one that contrasts sharply with the brute strength of other tribes. Rather than engaging in massive frontal assaults like a roaring lion, Dan’s power is defined by cunning, surprise, and calculated tactics. This strategy is captured through the imagery of two distinct venomous reptiles. The first represents a danger lurking on the main, wide highways, while the second lies in wait along narrow, hidden side paths [רש ר הירש, ביאור יש״ר]. This second creature is an exceptionally small viper, thin as a hair yet deeply venomous. It conceals itself completely in the sand, grass, or trees, unseen until it strikes its victim like an arrow [רמב״ן, ספורנו, שד״ל]. By its very nature, it crawls low and bent upon the ground, delivering a sudden, hissing strike [אבן עזרא, רש״י, גור אריה].

Historically and militarily, this perfectly describes Dan’s position as the rearguard of the Israelite camp and a defender of the borders. Their role is to protect the nation from behind and repel invaders. The method by which a tiny, weak snake defeats a mighty, mounted warrior is by striking at the horse's heels. Unable to attack the rider directly or wrap around the horse's massive belly, the snake delivers a sudden bite to the heel. This causes the horse to rear up in panic, throwing its rider backward to the ground [הטור הארוך, שד״ל, מלבי״ם]. In the same way, the tribe of Dan would harass their enemies from the rear, crippling the horses of the Philistines and bringing down their cavalry [נתינה לגר, מלבי״ם, בכור שור].

Beyond the general destiny of the tribe, the primary approach among commentators is that this blessing is a focused prophecy about Dan’s greatest hero, Samson. The lives and actions of Samson and the snake share several surprising parallels. First, unlike conventional kings and generals who lead massive armies into battle, a snake always travels alone. Similarly, Samson went out to strike the Philistines entirely by himself [רמב״ן, רד״ק, ספורנו]. Second, just as a snake lacks legs and crawls on its belly, tradition describes Samson as being lame in both of his legs [רבנו בחיי, תורה תמימה]. Furthermore, just as a snake strikes out of a natural instinct for vengeance, Samson acted out of a desire to take vengeance on God's enemies. Finally, just as a snake can be subdued by a charmer's whisper, Samson ultimately surrendered to the whispers and seductions of Delilah [רבנו בחיי, פרדס יוסף].

The climax of this prophetic comparison points directly to the heroic moment of Samson’s death. The image of the snake biting the horse's heels, causing the rider to fall backward, mirrors Samson’s final act. He grasped the two central pillars of the Philistine temple, which served as the foundational heels supporting the entire structure. By uprooting these heels, the multitude of Philistines standing on the roof—represented by the rider—all fell backward to their deaths. Through this final, devastating strike, Samson brought down more enemies in his death than he did throughout his entire life [רמב״ן, רבנו בחיי, רלב״ג, אלשיך].