ספר ויקרא is not known for its stories. In fact, there are only two of them in the entire ספר, one relating to the inauguration of the משכן (in פרשת שמיני) and the other in this week's פרשה. The problem is, the one in פרשת שמיני actually blends with the הלכות whereas the story of the מקלל in this week's פרשה seems to be completely out of context.
The story opens with a description of two people - one, a Jew indistinguishable from any other, the other a Jew whose father was an Egyptian and whose mother was from שבט דן. For some inexplicable reason the two argue publicly, and during that argument, the one with the Egyptian father expresses the name of God and curses.
There are few clues to unravel the mystery of this story and its inclusion in ספר ויקרא, which is precisely why the מדרשים and מפרשים struggled with the language used and the context. Perhaps, then, the only relevant information is that which the תורה tells us. Let us examine it.
ספר ויקרא is one whose primary theme is קדושה. קרבנות, כהנים, ארץ ישראל, משכן, מועדים reflect the notions of sanctity of objects, people, space and time. Jews themselves are bidden to endow their lives with sanctity, becoming קדוש in the process. Even the laws of כשרות and צרעת reflect the sanctity of the body. Interestingly, as the תורה introduced the concept of sanctity in our sexual lives in last week's פרשה, it instructs us to keep far away from the sexual practices of מצרים. Apparently, the תורה's concept of sanctity, which involves separation and distinction, was radically different from Egyptian religious notions.
Imagine, then, the reaction of a man whose father was an Egyptian and mother from שבט דן, the tribe of the assistant artisan of the משכן. His entire life, he might be torn between the religious sensitivities imbued by his mother and the Egyptian values of his father. At the same time, he cannot set his tent in the midst of the camp of the Jews (see the beginning of ספר במדבר). Hearing that the תורה demands that he must abandon half of his identity, an identity he is not permitted to forget, he confronts those who have no identity crisis (the איש הישראלי) in the middle of the camp (from which he is excluded), and explodes. Since there is no resolution to his identity crisis, he rebels against what he perceives to be the source of that crisis - the entire idea of קדושה.
And what form does that rebellion take? He explodes and publicly expresses the name of God, usually kept hidden and separate from the ears of mortals, thereby belittling it. That public expression is not only a rejection of the sanctity of God, but of all concepts of sanctity.
Interestingly enough, after the תורה instructs משה how to react to the מקלל, there is a brief reiteration of a seemingly unrelated set of מצוות. One who wounds an animal must pay, one who wounds another person deserves to have the same done to him, a murderer must pay with his life, and that all these rules apply equally to the convert and the native born Jew. In what way is this list internally consistent, and what connection does this have to the previous story?
I believe that the answer lay in the very definition of קדושה - sanctification through differentiation. In the Egyptian culture, humans could claim divinity and even animals were treated as gods. There were no quantum distinctions between the different forms of life. It was precisely this lack of differentiation of which the תורה warns, against which the מקלל rebelled and which the תורה reaffirms after the incident of the מקלל. Wounding an animal must be treated differently from wounding a human, killing an animal must have consequences fundamentally different from killing a human, and disgracing the name of God must be in a category of its own - and קדושה is an attainable goal for every human, whether a native born Jew or not.
The story at the end of the ספר reaffirms the notion of קדושה that is at the very core of the ספר, and of all of Jewish life.