וְהָיָה֙ כִּֽי־יֹאמְר֣וּ אֵלֶ֔יךָ עַל־מָ֖ה אַתָּ֣ה נֶאֱנָ֑ח וְאָמַרְתָּ֡ אֶל־שְׁמוּעָ֣ה כִֽי־בָאָ֡ה וְנָמֵ֣ס כָּל־לֵב֩ וְרָפ֨וּ כָל־יָדַ֜יִם וְכִהֲתָ֣ה כָל־ר֗וּחַ וְכָל־בִּרְכַּ֙יִם֙ תֵּלַ֣כְנָה מַּ֔יִם הִנֵּ֤ה בָאָה֙ וְנִֽהְיָ֔תָה נְאֻ֖ם אֲדֹנָ֥י יְהוִֽה׃ (פ)
И когда они скажут тебе: для чего ты вздыхаешь? что ты скажешь: из-за новостей для этого; и каждое сердце растает, и все руки будут ослаблены, и каждый дух будет слабым, и все колени будут капать водой; вот, это придет и будет сделано, говорит Господь Бог.'
Rashi
shall melt Shall melt - so explained Menachem, similar to (Exod. 15:15), “all the inhabitants of Canaan melted (נמוגו),” and to (Ezek. 21: 12), “every heart will melt (למוג).” But Dunash explained it as an expression of movement, as in (I Sam. 14:16), “the multitude was wandering (נמוג), and it was coming closer,” and so in every instance.
Rashi
Let them be rejected by themselves, that they will be rejected in their own eyes from worry, and as [if] in water let them walk. Similar to this is (Ezek. 7:17): “and all knees will go [as in] water,” from tears.
Chizkuni
אשכיר חצי מדם, “I will make My arrows drunk with blood.” Concerning this we read in Ezekiel 21,12: הנה באה ונהיתה נאם ה', “Behold!, it comes and has happened.” אשכיר חצי מדם, “how is it possible for arrows to become drunk with blood? The meaning is that G-d will make others drunk when they see what His arrows have accomplished. (Sifri)