49:17מ״ט:י״ז
1 א

שפיפן. הוּא נָחָשׁ; וְאוֹמֵר אֲנִי שֶׁקָּרוּי כֵּן עַל שֵׁם שֶׁהוּא נוֹשֵׁף, כְּמוֹ וְאַתָּה תְּשׁוּפֶנּוּ עָקֵב (בראשית ג'):

שפיפן is another name for a נחש. I am of opinion that it is thus called because it hisses (נושף) when biting. Similarly we have, (Genesis 3:15) “and thou shalt bite (תשיפנו) at their heel” (cf. Rashi thereon).

2 ב

הנשך עקבי סוס. כָּךְ דַּרְכּוֹ שֶׁל נָחָשׁ, וְדִמָּהוּ לְנָחָשׁ הַנּוֹשֵׁךְ עִקְּבֵי סוּס, ויפל רכבו אחור – שֶׁלֹּא נָגַע בּוֹ. וְדֻגְמָתוֹ מָצִינוּ בְּשִׁמְשׁוֹן: וַיִּלְפֹּת שִׁמְשׁוֹן אֶת שְׁנֵי עַמּוּדֵי הַתָּוֶךְ וְגוֹמֵר (שופטים ט"ז) – וְשֶׁעַל הַגַּג מֵתוּ; וְאֻנְקְלוֹס תִּרְגֵּם כְּחִוֵּי חוּרְמָן, שֵׁם מִין נָחָשׁ, שֶׁאֵין רְפוּאָה לִנְשִׁיכָתוֹ, וְהוּא צִפְעוֹנִי, וְקָרוּי חוּרְמָן עַל שֵׁם שֶׁעוֹשֶׂה הַכֹּל חֵרֶם; וּכְפִיתְנָא – כְּמוֹ פֶתֶן, יִכְמוֹן – יֶאֱרֹב:

הנשך עקבי סוס THAT BITETH THE HORSE’S HEELS — this is the manner of the serpent. Scripture compares him to a serpent that bites the horse’s heels ויפל רכבו אחור THAT HIS RIDER FALLETH BACKWARD without it (the serpent) having touched him at all. We find the analogy to this in the case of Samson with reference to whom this prophecy was made (Judges 16:29): “And Samson look fast hold of the two middle pillars etc.” — and those on the roof died though not directly attacked. Onkelos translates נחש by כחיוי חורמן, like the serpent “Churman”, which is the name of a kind of serpent the bite of which is incurable. It is the serpent which in Hebrew is called צפעוני. It is called a חורמן because it destroys (חרם) everything. The word וכפיתנא in the Targum means “and like a פתן” (like an asp). יכמון in the Targum means יארוב “he lies in wait”.