Deuteronomy 10:8 At that time the Lord separated the tribe of Levi, to bear the ark of the covenant of the Lord, to stand before the Lord to minister unto him, and to bless in his name, unto this day.
[Patriarchs & Prophets pp 705>706] The priests were to cover the ark, and then the Kohathites must lift it by the staves, which were placed in rings upon each side of the ark and were never removed. To the Gershonites and Merarites, who had in charge the curtains and boards and pillars of the tabernacle, Moses gave carts and oxen for the transportation of that which was committed to them. “But unto the sons of Kohath he gave none: because the service of the sanctuary belonging unto them was that they should bear upon their shoulders.” Numbers 7:9.
Thus in the bringing of the ark from Kirjath-jearim there had been a direct and inexcusable disregard of the Lord's directions. David and his people had assembled to perform a sacred work, and they had engaged in it with glad and willing hearts; but the Lord could not accept the service, because it was not performed in accordance with His directions. The Philistines, who had not a knowledge of God's law, had placed the ark upon a cart when they returned it to Israel, and the Lord accepted the effort which they made.
But the Israelites had in their hands a plain statement of the will of God in all these matters, and their neglect of these instructions was dishonoring to God. Upon Uzzah rested the greater guilt of presumption. Transgression of God's law had lessened his sense of its sacredness, and with unconfessed sins upon him he had, in face of the divine prohibition, presumed to touch the symbol of God's presence.
2nd Samuel 6:9 And David was afraid of the Lord that day, and said, How shall the ark of the Lord come to me? 10 So David would not remove the ark of the Lord unto him into the city of David: but David carried it aside into the house of Obededom the Gittite.
May The Lord add His blessing to the study of His word. God bless!