כִּי֩ הִנְנִ֨י מְשַׁלֵּ֜חַ בָּכֶ֗ם נְחָשִׁים֙ צִפְעֹנִ֔ים אֲשֶׁ֥ר אֵין־לָהֶ֖ם לָ֑חַשׁ וְנִשְּׁכ֥וּ אֶתְכֶ֖ם נְאֻם־יְהוָֽה׃ (ס)
װאָרום זעט, איך שיק אָן אױף אײַך שלענג פּיפּערנאָטערס, װאָס פֿאַר זײ איז קײן שפּרוך ניטאָ, און זײ װעלן אײַך בײַסן, זאָגט גאָט.
Rashi
serpents, adders After seventy years, the snake becomes a צפע, which shuts its ear so that it will not hear the voice of the charmer who charms him, as it is stated (Psalms 58:5), “Like a deaf asp that shuts up its ear.” That is the meaning of “that cannot be charmed.”