The Life of Flavius Josephus (101)

But now John was afraid for himself, since his treachery had proved unsuccessful. So he took the armed men that were about him, and removed from Tiberias to Gischala, and wrote to me to apologize for himself concerning What had been done, as if it had been done without his approbation, and desired me to have no suspicion of him to his disadvantage. He also added oaths and certain horrible curses upon himself, and supposed he should be thereby believed in the points he wrote about to me.