כִּי֩ כֹ֨ה אָמַ֤ר יְהוָה֙ אֱלֹהֵ֣י יִשְׂרָאֵ֔ל עַל־בָּתֵּי֙ הָעִ֣יר הַזֹּ֔את וְעַל־בָּתֵּ֖י מַלְכֵ֣י יְהוּדָ֑ה הַנְּתֻצִ֕ים אֶל־הַסֹּלְל֖וֹת וְאֶל־הֶחָֽרֶב׃
For thus saith the LORD, the God of Israel, concerning the houses of this city, and concerning the houses of the kings of Judah, which are broken down for mounds, and for ramparts;
Rashi on Jeremiah
that are demolished for the mounds To make mounds of them, mounds piled up high which the city dwellers build to ascend the mounds to wage war from upon them with the Chaldeans.
Rashi on Jeremiah
and for the sword To strengthen the wall against those who slay with the sword.