15 Then Joshua made a treaty of peace with them to let them live, and the leaders of the assembly ratified it by oath.

Read Joshua 9:15 Using Other Translations

And Joshua made peace with them, and made a league with them, to let them live: and the princes of the congregation sware unto them.
And Joshua made peace with them and made a covenant with them, to let them live, and the leaders of the congregation swore to them.
Then Joshua made a peace treaty with them and guaranteed their safety, and the leaders of the community ratified their agreement with a binding oath.