Why does O Henry call Della and Jim wise?

In "The Gift of the Magi", O. Henry refers to Della and Jim as "wise" because of their selfless love and devotion to each other. Despite their poverty, they are willing to sacrifice their most valuable possessions in order to give each other a gift for Christmas. This act of selflessness demonstrates their deep understanding of the true meaning of love and gift-giving, which is not about the material value of the gift but the thought and care behind it. By recognizing the significance of their actions and appreciating their love for each other, O. Henry highlights their wisdom in understanding what truly matters in life.