וַיֵּצֵא בֶּן אִשָּׁה יִשְׂרְאֵלִית וְהוּא בֶּן אִישׁ מִצְרִי בְּתוֹךְ בְּנֵי יִשְׂרָאֵל וַיִּנָּצוּ בַּמַּחֲנֶה בֶּן הַיִּשְׂרְאֵלִית וְאִישׁ הַיִּשְׂרְאֵלִי. יא וַיִּקֹּב בֶּן הָאִשָּׁה הַיִּשְׂרְאֵלִית אֶת הַשֵּׁם וַיְקַלֵּל וַיָּבִיאוּ אֹתוֹ אֶל מֹשֶׁה וְשֵׁם אִמּוֹ שְׁלֹמִית בַּת דִּבְרִי לְמַטֵּה דָן
Now the son of an Israelite mother and an Egyptian father went out among the Israelites, and a fight broke out in the camp between him and an Israelite. 11The son of the Israelite woman blasphemed the Name with a curse; so they brought him to Moses. His mother’s name was Shelomith, the daughter of Dibri the Danite. (NIV)
Although most translations agree that the Egyptian blasphemed the Name of God, and traditionally this has been the accepted translation, there is no textual evidence to support that. As the Cambridge Bible Commentary points out, the word וַיִּקֹּב most likely means "to indicate by name", (cf. Numbers 1:17, see also Abu Munir's response here), thus a translation more loyal to the text would read something like "and he uttered the name and cursed". Ostensibly, uttering the name would refer to the tetragrammaton, not just any name.
Translated this way, it is not at all evident that the Egyptian cursed the name of God, it actually seems more likely now that he cursed the Israelite, that he was fighting with, by uttering the name of Yahweh, saying for example "may Yahweh strike you dead", or something to that effect. This was considered a grave sin in the Mosaic code of law. We find similar laws against cursing a deaf man (Lev. 19:14), cursing the elder (Ex. 22:27), or cursing a judge (ibid), and we even find the death penalty on one who curses his parents (Ex. 21:17), so it should come as no surprise that if one curses his fellow Israelite by the name Yahweh that he should be stoned to death, as harsh as the punishment may seem to us.
This actually explains why he cursed the Israelite, it always bothered me why he would curse God while fighting with an Israelite, especially since the Egyptian himself was half Israelite and probably accepted Mosaic religion as well and feared Yahweh. But if we interpret this verse as him cursing the Israelite by uttering the name of Yahweh, that would explain a lot.
It also explains why in the middle the text interjects with laws regarding hitting and inflicting harm on humans and cattle:
Say to the Israelites: ‘Anyone who curses their God will be held responsible; 16anyone who utters the name of the Lord [in blasphemy] is to be put to death. The entire assembly must stone them. Whether foreigner or native-born, when they blaspheme the Name they are to be put to death.
17“ ‘Anyone who takes the life of a human being is to be put to death. 18Anyone who takes the life of someone’s animal must make restitution—life for life. 19Anyone who injures their neighbor is to be injured in the same manner: 20fracture for fracture, eye for eye, tooth for tooth. The one who has inflicted the injury must suffer the same injury. 21Whoever kills an animal must make restitution, but whoever kills a human being is to be put to death.
It's strange that the text should veer off in the middle and talk about laws involving actions which inflict harm on other humans, when the focus of the text is to ban and punish the one who blasphemes the name of god. However, if my theory is correct then it makes perfectly sense why these laws are grouped together; cursing someone is also viewed as a form of violence and immoral behavior. In other words, just like you wouldn't hit someone or harm anyone, so too you should refrain from cursing anyone (especially by uttering the holy name) as this will surely cause harm to the other person.
So is it possible that the Egyptian cursed the Israelite, not Yahweh himself, by invoking the holy name of Yahweh? Does the text support such a reading? And is is such a reading more loyal to the text than the traditional interpretation?
I'm aware that v. 15 poses a problem to my theory, however this can be easily rectified by slightly emending the text אִישׁ כִּי יְקַלֵּל אֱלֹהָיו. If we add the letter בּ to the word אֱלֹהָיו, we get the word בֵּאלֹהָיו, which yields "one who curses by his God". It is actually used in this exact sense in 1 Samuel 17:43.