“When they came to the threshing floor of Chidon, Uzzah put out his hand to hold the ark, for the oxen shook it. The anger of Yahweh was kindled against Uzzah. He struck him down because he put out his hand to the ark. He died there before God. King David was angry because Yahweh had burst out against Uzzah. That place is called Perez-uzzah to this day.”
Here the name of the threshing floor is Chidon and not Nacon as in 2 Samuel, chapter 6. Both places only occur once. Uzzah reached out to steady the Ark of the Covenant as the cart must have hit a few bumpy spots or some pot-holes. Anyway, Uzzah tried to stabilize the Ark of the Covenant. Yahweh was angry and struck Uzzah dead for touching the sacred Ark of the Covenant, which was forbidden even to the Levites. There had been other incidents in 1 Samuel where the Ark of the Covenant caused destruction. King David, however, was also angry because this ruined the celebration. He called that place Perez-uzzah.