Jeremiah 33:4

4 For this is what the LORD, the God of Israel, says about the houses in this city and the royal palaces of Judah that have been torn down to be used against the siege ramps and the sword

Read Jeremiah 33:4 Using Other Translations

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 thrown down by the mounts, and by the sword;
For thus says the LORD, the God of Israel, concerning the houses of this city and the houses of the kings of Judah that were torn down to make a defense against the siege mounds and against the sword:
For this is what the LORD, the God of Israel, says: You have torn down the houses of this city and even the king’s palace to get materials to strengthen the walls against the siege ramps and swords of the enemy.

What does Jeremiah 33:4 mean?

John Gill's Exposition of the Bible
Jeremiah 33:4

For thus saith the Lord, the God of Israel
The destruction of Jerusalem by the Chaldeans, which was now fulfilling, is here mentioned as a pledge of the accomplishment of spiritual blessings after spoken of; and to assure the prophet, that as he would with his own eyes see the fulfilment of the prophecies he had delivered out in the name of the Lord concerning that, so likewise as certainly would the other be brought to pass: concerning the houses of this city, and concerning the houses of the
kings of Judah, which were thrown down by the mounts, and by the sword;
by "the mounts", which the Chaldeans raised without the city; or by the engines they placed there, by which they cast out stones into the city, to the demolishing of the houses in it; not in common only, but particularly the houses of the king and nobles, which they especially directed their shot at; and by "the sword", hammers, axes, and mattocks, for which sometimes this word is used, when they entered into the city. Though some render the words, "which are thrown down for mounts, and for the sword" F18; that mounts might be made of them within, on which the Jews might fight and defend themselves against the Chaldeans. So the Targum,

``which they pulled down, and threw up mounts to strengthen the wall, against those that kill with the sword;''
and so Jarchi interprets it.
FOOTNOTES:

F18 (brxh law twlloh la) "ad aggeres et vastitatem", Tigurine version; "in missilia catapultaria, et in gladium", Junius & Tremellius; "ad catapultas, et ad gladium", so some in Calvin.
California - Do Not Sell My Personal Information  California - CCPA Notice