1 Chronicles 23:5-7

Young's Literal Translation

⁵ and four thousand gatekeepers, and four thousand giving praise to Jehovah, `with instruments that I made for praising,' [saith David.]

⁶ And David distributeth them into courses: Of the sons of Levi: of Gershon, Kohath, and Merari.

⁷ Of the Gershonite: Laadan and Shimei.