1 Chronicles 15:26

And it came to pass, when God helped the Levites that bare the ark of the covenant of the LORD, that they offered seven bullocks and seven rams.

It came to pass ... - (see the notes at 2 Samuel 6:13.)

They offered seven buttocks and seven rams. The Levites seem to have entered on this duty with fear and trembling; and finding that they might advance without any such indications of divine wrath as Uzzah had experienced (1 Chronicles 13:10), they offered an ox and a fatted sheep immediately after starting (2 Samuel 6:13), and seven bullocks and seven rams-a perfect sacrifice-at the close of the procession (1 Chronicles 16:1). It is probable that preparations had been made for the offering of similar sacrifices at regular intervals along the way.