Naaman foresees a major problem. He knows that now he has been cleansed and healed, and due to his high position, that his king will take him to the temple of Rimmon to bow down in front of the image of this god. How can he reconcile this with his profession of faith in the Lord? So he asks, twice, for forgiveness, before he will find himself in this difficult position! The inclusio (see Technical and Hermeneutical section) underscores this cry for forgiveness.
18 In this matter may the LORD pardon your servant: when my master goes into the house of Rimmon to worship there, leaning on my arm, and I bow myself in the house of Rimmon, when I bow myself in the house of Rimmon, the LORD pardon your servant in this matter.”