As was mentioned in the previous post, Polonius is giving his son, Laertes, advice before he leaves for France in Act One, Scene 3. Shakespeare intended this scene to bring some comic relief to the play by having the pompous, simple-minded Polonius give his son some long-winded advice. Polonius tells his son, among other things, that he should listen, rather than speak, and that he should spend most of his money on quality clothing. Shakespeare writes,

"Costly thy habit as thy purse can buy, but not expressed in fancy—rich, not gaudy, for the apparel oft proclaims the man, and they in France of the best rank and station are of a most select and generous chief in that" (1.3.71-75).

Essentially, Polonius is telling his son the common idiom, "the clothes make the man." Polonius believes that the French citizens will judge Laertes on his appearance and instructs him to buy quality clothes that will impress others. Following Polonius' logic, Laertes will be judged on the clothes he wears instead of his personal attributes. This shallow advice correlates with Polonius' character throughout the play and provides comic relief to a rather sad piece of drama.