Then David said that no one but the Levites may carry the ark of God, for the LORD had chosen them to carry the ark of the LORD and to minister to him forever.
Preparation is here made for the bringing of the ark home to the city of David from the house of Obed-edom. It is here owned that in the former attempt, though it was a very good work and in it they sought God, yet they sought him, not after the due order, Ch1 15:13.
Commenting on 1 Chronicles 15:1-24
Then David said,.... Either within himself, or to his ministers and courtiers about him: none ought to carry the ark of God but the Levites; he saw his former mistake in employing those that were not Levites in bringing up the ark from Kirjathjearim, and bringing it in a cart, and not on the shoulders of the Levites, and so miscarried in his attempt, Sa2...
Then David said, None ought to carry the ark of God but the Levites--After the lapse of three months (Ch1 13:14) the purpose of transporting the ark to Jerusalem was resumed. Time and reflection had led to a discovery of the cause of the painful catastrophe that marred the first attempt.