Joshua 9:18-20

18But Bnei-Yisrael did not strike them, because the leaders of the community had sworn to them by Adonai, God of Israel. Then the entire community murmured against the leaders,

19but all the leaders answered the entire community, “We have sworn to them by Adonai, God of Israel, so now we cannot touch them.

20This is what we will do to them: We will let them live, lest wrath be upon us because of the oath which we swore to them.”