Jeremiah 40:15-16

Then Johanan the son of Kareah spoke secretly to Gedaliah at Mizpah, “Please let me go and strike down Ishmael the son of Nethaniah, and no one will know it. Why should he take your life, so that all the Judeans who are gathered about you would be scattered, and the remnant of Judah would perish?” But Gedaliah the son of Ahikam said to Johanan the son of Kareah, “You shall not do this thing, for you are speaking falsely of Ishmael.”