Since Artaxerxes was left with debts after the death of Xerxes and rebellions in Egypt, the Persian king would be eager to ensure no further threat of a loss of revenue or territory should happen. Rehum is thus very clever in appealing to the king’s concern over money and power.
13 Now be it known to the king that if this city is rebuilt and the walls finished, they will not pay tribute, custom, or toll, and the royal revenue will be impaired.