1 Chronicles 4:41

4:41 The men whose names are listed came during the time of King Hezekiah of Judah and attacked the Hamites’ settlements, as well as the Meunites they discovered there, and they wiped them out to this very day. They dispossessed them, for they found pasture for their sheep there.

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.