וַיִּֽחַר־אַ֤ף יְהוָה֙ בְּעֻזָּ֔ה וַיַּכֵּ֥הוּ שָׁ֛ם הָאֱלֹהִ֖ים עַל־הַשַּׁ֑ל וַיָּ֣מָת שָׁ֔ם עִ֖ם אֲר֥וֹן הָאֱלֹהִֽים׃
永恆者的怒氣向烏撒發作，上帝因他的過失在那裡擊殺了他；他就死在那裡，在上帝的約櫃旁邊。
Tze'enah Ure'enah
“The Lord was angry at Uzzah, etc.” [6:7]. The Holy One killed Uzzah because he thought that the Ark would fall. He should have thought that the Ark was very holy and it would not fall, even if the oxen would fall. The Holy One said that the Ark carried the people who carried it. In any event, it would carry itself and would not fall. He punished Uzzah there, near the Ark.3Radak, II Samuel, 6:7.
Rashi
Because of his mistake. Because of his mistake, he should have expounded a fortiori [as follows:] the Ark carried its own porters in the Yardein,7When Bnei Yisroel crossed the Yardein into the land of Yisroel as stated in Yehoshua 4:11 and explained in Sotah, ibid. isn't it all the more so [that it is able to carry] itself.