1 Chronicles 12:17-19

12:17 David went out to meet them and said, “If you come to me in peace and want to help me, then I will make an alliance with you. But if you come to betray me to my enemies when I have not harmed you, may the God of our ancestors take notice and judge!” 12:18 But a spirit empowered Amasai, the leader of the thirty warriors, and he said:

“We are yours, O David!

We support you, O son of Jesse!

May you greatly prosper!

May those who help you prosper!

Indeed your God helps you!”

So David accepted them and made them leaders of raiding bands.

12:19 Some men from Manasseh joined David when he went with the Philistines to fight against Saul. (But in the end they did not help the Philistines because, after taking counsel, the Philistine lords sent David away, saying: “It would be disastrous for us if he deserts to his master Saul.”)

1 Chronicles 23:28

23:28 Their job was to help Aaron’s descendants in the service of the Lord’s temple. They were to take care of the courtyards, the rooms, ceremonial purification of all holy items, and other jobs related to the service of God’s temple.