15:1-24 Wise and good men may be guilty of oversights, which they will correct, as soon as they are aware of them. David does not try to justify what had been done amiss, nor to lay the blame on others; but he owns himself guilty, with others, of not seeking God in due orderThe "due order" was that the ark should be borne on the shoulders of Kohathite Levites - not that it should be placed upon a cart, drawn by oxen, and rudely shaken. 12. sanctify yourselves—This special sanctification, which was required on all grave and important occasions, consisted in observing the strictest abstinence, as well as cleanliness, both in person and dress (see on [380]Ge 35:2; Ex 19:10, 15); and in the neglect of these rules no step could have been taken (2Ch 30:3). No text from Poole on this verse.

So the priests and the Levites sanctified themselves,.... As they were ordered, and in the manner they should:

to bring up the ark of the Lord God of Israel; for though it was chiefly the work of the Levites, yet the priests might do it, and sometimes did, see Joshua 3:13.

So the priests and the Levites sanctified themselves to bring up the ark of the LORD God of Israel.