Charles Ellicott Commentary 2 Samuel 6:4

"And they brought it out of the house of Abinadab, which was in the hill, with the ark of God: and Ahio went before the ark." — 2 Samuel 6:4 (ASV)

And they brought it. —The text has undoubtedly suffered here through the repetition of a line by the scribes. The whole verse is omitted in the parallel passage in 1 Chronicles 13:0, and the first half of it (which is a repetition of 2 Samuel 6:3) in the Septuagint.