Jeremiah 40:13, 15

One day Johanan son of Kareah and all the military leaders still in the field came to Mizpah to meet with Gedaliah.

So Johanan went privately and approached Gedaliah, saying, “Please let me go and kill Ishmael son of Nethaniah, and no one will know who did it. Why should he assassinate you and scatter all the Israelites who have rallied around you? Why should the remnant of Judah perish?”