What is the difference between a "Nachash" and a "Shefifon"?
Rashi #1: They are really one and the same, and the Torah refers to it as Shefifon because it makes a hissing sound (when it strikes). 1
Rashi #2 (citing Targum Onkelos) and Targum Yonasan: Like a viper 2 that waits by the wayside, and a cobra that lies in ambush on the path (of whom the nations are terrified and who strikes the Pelishtim).
Ramban and Seforno: Like a viper 3 that waits by the wayside, and like a tiny snake as thin as a hair, 4 that hides in a tree and to cast itself like an arrow upon any passing creature. 5
Rashbam: Like a snake kills all who pass by the wayside, so too, will the tribe of Dan kill all their enemies. 6
Malbim: In size they were like Nechashim (big snakes). Regarding Derech they were like a Shefifon (small snake, which goes stealthily from the side).
As we find in Bereishis (3:15).
Whose bite is incurable. Targum translates it as Churman (the term used by Arab doctors [Seforno]), because it destroys all. The Seforno adds that it is kills many in one go with its look and with its voice, which is why it characterizes Shimshon, who was capable of fighting the enemy.
Refer to 49:17:1:2*.
Yerushalmi, Terumos 5:8.
Seforno: Likewise Shimshon, who fought on his own, unseen by his enemies as he suddenly swooped down upon them.
The Rashbam does not comment on the details described in the Pasuk.
Why does Yaakov compare Dan to "a snake on the road... that bites the horse's heels, causing the rider to fall backwards"?
Rashi, Ramban and Targum Yonasan: Just as a snake causes the rider to fall 1 without actually touching him, so too, did Shimshon bring about the death of the three thousand Pelishtim on the roof without touching them. 2
Targum Onkelos: [Shimshon] kills the mighty men of the Pelishti camp, cavalry and infantrymen; he destroys the horses and the chariots - and he causes the chariot-riders to fall backwards.
Rashbam: The enemy falls before them. 3
Malbim: Those who attack a Machaneh from the back, ride on horses. Dan went by foot. They cut off the horses' legs with a sword, and the riders fell into their hands.
Ha'amek Davar: Just like the power of Torah helps for Yisrael's wars, also the power of judgment. Matan Torah is written between Dinim - after appointing judges, and before Parshas Mishpatim. "Dan Din Oni v'Evyon... Hi ha'Da'as Osi" (Yirmeyah 22:16). I.e. judging is like the power of Torah, which is knowing Elokim. Dan fights like a snake on the road - it kills many when it is alone. So Shimshon will kill 1000 men with a donkey's jawbone. When a horse goes over a snake, it bites the ankle. The horse falls, and its rider falls back. So when the Pelishtim lowered Shimshon and trampled him, he 'bit' the 'heels' of the house (i.e. toppled the pillars), and they all fell. Also Moshe blessed Dan with weak strength, and not like the strength of Yehudah, which was based on the power of Torah.
Ramban: When the horse raises its head and forelegs into the air.
By toppling the two central pillars (hinted at here in the words, "the heels of the horse" [Ramban]), as described in Shoftim 16:29.
The Rashbam explains only briefly.
QUESTIONS ON RASHI
Rashi writes: "Shefifon - A snake... is so called because it is Noshef (it hisses)." But the Shoresh (root) of the word 'Shefifon' is Shin-Fey-Fey, whereas the root of 'Noshef' is Nun-Shin-Fey?
Gur Aryeh: The letter Nun often falls out of a root (as do letters Vav and Yud), or sometimes a root contains a doubled letter. This shows that the essential root of these words is just two letters; in this case, Shin-Fey. 1 Rashi may therefore derive its meaning from any such Shin-Fey word.
Although most authorities classify verbs in Lashon ha'Kodesh into three-letter roots, notable proponents of the two-letter root approach are Menachem ibn Saruk (Spain, 10th c.), who is often quoted by Rashi; and later, R. Shlomo Poppenheim (Prussia, 18th c.), frequently cited in the work Ha'Kesav Veha'kabalah. (CS)
Rashi writes: "Shefifon -A snake... so called because it is Noshef (it hisses)." Is there another way to explain?
Gur Aryeh: (Unlike Rashi), one may explain that a Shefifon always drags ('Shaf') its belly along the ground; this is the meaning of the verb Shin-Fey. 1
Ha'Kesav Veha'kabalah (to Vayikra 13:45, citing R. S. Poppenheim): Whereas most snakes lift some part of their body off of the ground, the Shefifon does not raise it at all. Related words include the animal 'Shafan,' and the 'Ashaf' magician who walks dragging his feet (e.g. Bil'am, who walked 'Shefi' - Bamidbar 23:3). (CS - See Yalkut Shorashim (Steinberg))
