Jeremiah 41:1-3

In the seventh month Ishmael the son of Nethaniah, the son of Elishama, of the royal family and one of the chief officers of the king, along with ten men, came to Mizpah to Gedaliah the son of Ahikam. While they were eating bread together there in Mizpah, Ishmael the son of Nethaniah and the ten men who were with him arose and struck down Gedaliah the son of Ahikam, the son of Shaphan, with the sword and put to death the one whom the king of Babylon had appointed over the land. Ishmael also struck down all the Jews who were with him, that is with Gedaliah at Mizpah, and the Chaldeans who were found there, the men of war.