In "The Gift of the Magi," why are Jim and Della compared to the Magi? How are they the wisest?

The point that O. Henry makes about gift-giving in "The Gift of the Magi" is one that has been tritely summed up with the aphorism, "It's the thought that counts." In the cases of Jim and Della, the thought behind the gifts had to suffice because the gifts themselves ended up being useless. Della cut her long, beautiful hair, her most prized possession, so that she could afford to buy Jim a chain for his watch, which was his most prized possession. For his part, Jim pawned his watch so that he could buy the decorative combs that would look so lovely in Della's long hair—which now no longer exists. The ironic outcome that made the gifts useless nevertheless showcased the depth of the sacrifice behind the gifts. Della and Jim each gave up her or his most prized possession in order to secure a gift that would bring joy to the other.
In the final paragraph of the story, Henry compares Della and Jim to the Magi. He states that the Magi, or biblical Wise Men, began the tradition of giving Christmas gifts. He points out that although Jim and Della's way of giving gifts may seem foolish because of the unexpected outcome, in reality, it was as wise as anything done by the Wise Men because it showed a willingness to give despite great personal cost. When Henry writes, "And here I have lamely related to you the uneventful chronicle of two foolish children in a flat who most unwisely sacrificed for each other the greatest treasures of their house," he is using verbal irony. Their sacrifice was not unwise. On the contrary, they showed wisdom like that of the renowned Wise Men, the Magi.