The third line is the most comfortable position in Grace and the text immediately attaches a condition to it. Legge's translation shows a subject with the appearance of being adorned and bedewed with rich favours, then instructs him to maintain firm correctness continually, after which there is good fortune. Bedewed is the important word. Dew settles gently, it comes from outside, and it does not last past the morning unless something replaces it.
The structure explains where the favours come from. This firm stroke stands at the top of the lower trigram Li with a yielding line directly below it and another directly above, so it is attended on both sides at once. That is a pleasant arrangement and a slightly precarious one, since a position sustained by the goodwill of its neighbours depends on goodwill continuing. The hexagram of ornament reaches, at this line, the point where being decorated becomes agreeable enough to be dangerous.
The instruction is therefore about duration rather than conduct. Firm correctness is not offered here as a way of earning the favours, which have already arrived, but as the only thing that keeps them from becoming the whole of the position. Good fortune is granted on a continuing basis, renewed as long as the constancy is renewed, and it is withheld from anyone who mistakes the dew on the surface for something they have grown themselves.