1 Chronicles 23:5-7
New International Version - UK
5 Four thousand are to be gatekeepers and four thousand are to praise the Lord with the musical instruments I have provided for that purpose.’
6 David separated the Levites into divisions corresponding to the sons of Levi: Gershon, Kohath and Merari.
7 Belonging to the Gershonites:
Ladan and Shimei.