כֹּ֣ה ׀ אָמַ֣ר יְהוָ֗ה אִם־שְׁלֵמִים֙ וְכֵ֣ן רַבִּ֔ים וְכֵ֥ן נָגֹ֖זּוּ וְעָבָ֑ר וְעִ֨נִּתִ֔ךְ לֹ֥א אֲעַנֵּ֖ךְ עֽוֹד׃
Thus saith the LORD: Though they be in full strength, and likewise many, Even so shall they be cut down, and he shall pass away; And though I have afflicted thee, I will afflict thee no more.
Rashi on Nahum
Though they be at peace and likewise many Jonathan’s Targum is very appropriate to the verse: If they [the people of Nineveh] are at peace in their counsel, that they will all be of one accord; and likewise, if the people of Nineveh, your enemies, are many, O Jerusalem; and likewise, even if they have crossed the Tigris and passed over the Euphrates to besiege it, they will not succeed, for I have afflicted you; I will no longer afflict you. I have heard further (this rendering): If they are perfect—the people of Nineveh, in their greatness. and likewise—if they will be still greater and more honored. and so they shall be cut down and pass away—And so I will cut them down and take them away. This is like (Exod 1:12) “And the more they would afflict them, the more they would multiply.”
Rashi on Nahum
and I will no longer afflict you—I will afflict you this time with destruction and annihilation, and I will no longer be involved with you. Our Sages expounded upon this concerning the practice of charity in Tractate Gittin (7a), but it does not fit in with the context.