Is the booty acquired by a group entering enemy territory without the Imam's permission subject to Khums?

Primary text

The correct ruling is that any spoils acquired by a group who enter the lands of war (Dar al-Harb) without the Imam's permission must have the Khums taken from it, and four-fifths are returned to them. This is because the acquisition falls under the general scope of the Quranic verse regarding Khums, and there is no textual evidence that warrants exempting it.