2 Samuel 6:7

The anger of the Lord was kindled against Uzzah For his rashness in touching the ark. Some have thought it was because he was not a Levite, and therefore should not have touched it. But it is pretty plain he was, being the brother of Eleazar, who, as a Levite, was consecrated to take care of the ark, 1 Samuel 7:1. But, although a Levite, he was guilty of a double error; first, in not carrying the ark upon his shoulders, together with his brethren; which their neglecting to do, on this solemn occasion, and consulting their ease more than their duty, was an offence of no small aggravation. Secondly, in touching it, which even the Levites were prohibited from doing, under the express penalty of death, Numbers 4:15. And this penalty, being incurred by a violation of that prohibition, was justly inflicted by him that threatened it, as an example to others, and to preserve a due reverence to the institution; especially as this, it appears, was the first instance of such violation. Add to this, the infliction of the penalty in this extraordinary way, manifested the prohibition to be divine; and as David himself, and the whole house of Israel, by their heads and representatives, were present at this solemnity, the nature of the punishment, and the reason why it was executed, would be made very public. Some have observed, thirdly, that Uzzah discovered by this action his want of faith, in the presence of God with the ark, and in his power, as if he were not able to preserve that sacred symbol of his presence from falling without Uzzah's helping hand. Uzzah, therefore, they say, was thus punished to teach and impress on the minds of the people, that God was peculiarly present with the ark, in order that they might be deterred from breaking any of his laws, or profaning sacred things. It may not be improper to add to the above the following observations from Poole. “God's smiting Uzzah, so that he instantly died by the ark, may seem very severe, considering his intention was pious, and his transgression not great. But, besides that men are improper judges of the actions of God; and that God's judgments are always just, though sometimes obscure; it is reasonable God should make some present examples of his high displeasure against sins seemingly small; partly for the demonstration of his own exact and impartial holiness; and partly for the establishment of discipline, and for the greater terror and caution of mankind, who are very prone to have slight thoughts of sin, and to give way to small sins, and thereby to be led on to greater; all which is, or may be, prevented by such instances of severity; and consequently there is more of God's mercy than of his justice in such actions, because the justice is confined to one particular person, but the benefit of it is common to mankind in that and all future ages.”