Of course the function of these verses has nothing to do with discussing horses and chariots, but rather to further show the faithfulness of Ammon. The king is amazed that a man who has so recently performed such a heroic feat is now simply attending to his next task. It would be human nature to want to wait around for some praise for such a mighty deed. In fact, it would be human nature to expect perhaps some reward for such a tremendous labor. Ammon, however, does none of these forgivably human possibilities. He simply goes about his work as though nothing special has happened, and the king understands that this may be the most remarkable thing of all. Ammon has, in this small thing, further demonstrated his loyalty to the king by such a simple thing as obedience.