1 Chronicles 12:18

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.

1 Chronicles 12:21

12:21 They helped David fight against raiding bands, for all of them were warriors and leaders in the army.