RobH_en_tn/jer/43/12.md

Then I will light a fire

Here "I" refers to Yahweh. This represents Yahweh sending the Babylonian army to light a fire. Alternate translation: "Then I will cause the Babylonian army to light a fire" (See: rc://en/ta/man/translate/figs-metonymy)

Nebuchadnezzar will ... He will

Here Nebuchadnezzar represents his army. Alternate translation: "Nebuchadnezzar's army will ... They will" (See: rc://en/ta/man/translate/figs-metonymy)

burn them or capture them

"burn the Egyptian idols or take them"

He will clean out the land of Egypt just as shepherds clean vermin off their clothes

Taking or destroying everything in Egypt is compared to how a shepherd carefully cleans off his clothes. Alternate translation: "He will take or destroy everything valuable in Egypt just as a shepherd is careful to get every insect off of his clothes" (See: rc://en/ta/man/translate/figs-simile)