In "The Gift of the Magi," O. Henry most likely uses the irony of the couple’s gifts to express the theme that

Della sells her beautiful hair to buy Jim a chain for his watch, while Jim sells his watch to buy combs for Della’s hair. Their gifts cannot be used as intended, which is ironic, but each gave up a prized possession to make the other happy. The story therefore suggests that love and sacrifice for others is the highest virtue, not that expensive gifts are simply a mistake.

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