God takes on the role of a military commander, actively rousing an enemy army to lay siege to Jerusalem. This impending destruction is not a random act of war, but a direct and calculated punishment for the deep moral corruption that has infected the city [רד״ק, ביאור שטיינזלץ].
The opening order of this divine military campaign is a command to cut down the abundant trees surrounding Jerusalem to gather timber for the siege [רש״י, רד״ק, מלבי״ם]. This directive presents a striking departure from standard biblical law, which strictly forbids the destruction of fruit trees during wartime. However, in this specific instance, God explicitly reverses that rule. The decree of destruction is aimed not just at the inhabitants, but at the city itself, which is marked for total ruin [מלבי״ם]. There is also a profound sense of poetic justice in this command. The residents of Jerusalem had previously stolen wood from others to construct their grand palaces. As a direct consequence, the enemy forces are now ordered to tear down those very structures, using the stolen timber to build their siege engines [חומת אנך].
Following the gathering of timber, the invading army is instructed to construct a massive siege mound. The attackers fill the protective trenches around Jerusalem with a mixture of dirt, stones, and wood. They continue to pile these materials higher and higher until the artificial hill reaches the top of the city walls, creating a ramp for the soldiers to storm the defenses and breach the city [רד״ק, מצודת דוד, מלבי״ם, ביאור שטיינזלץ].
The justification for this absolute devastation lies in the city's internal decay. God has closely watched and examined Jerusalem, and His patience has finally reached its end; the time for accountability has come [רש״י, מצודת ציון, רד״ק]. The city itself serves as a stark reminder of the sins committed within its borders [מלבי״ם]. It is entirely consumed by robbery and oppression. This corruption is not merely a danger lurking on the lawless roads outside the gates, but a rot that has settled deeply into the very heart of the city, present in every corner and on every street [רד״ק].