'Ministry' in the Bible

The priests stood at their posts [ready for service], and the Levites also, with the musical instruments of the Lord which King David had made to praise the Lord, saying, “For His lovingkindness and mercy endure forever,” whenever David offered praise through their ministry. The priests were opposite the Levites blowing the trumpets and all Israel was standing.

“It [their ministry to Me] shall be as an inheritance to them, for I am their inheritance; and you shall give them no property (land) in Israel, for I am their possession.