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. 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.
The verse belongs to the account of David bringing the ark from Kirjath-jearim to Jerusalem, and more particularly to its removal from the house of Obed-edom to Jerusalem where David placed it in a tabernacle he had pitched for it. The first removal had been interrupted after Uzzah was struck dead for touching the ark, so David left it at the house of Obed-edom. After the Lord blessed that household, David brought the ark to Jerusalem with gladness.
That bringing up marked its return to Israel's public worship after it had been taken by the Philistines and kept at Kirjathjearim and at Obed-edom. The event was part of David's organization of the Levites and musicians for worship. God helped the Levites as they bore the ark of the covenant of the Lord according to the order and prescribed manner He had given.
The carrying was accompanied by the offering of seven bullocks and seven rams. That help and those offerings show God's approval of the ark's removal once David obeyed the prescribed manner of carrying it.