Gedaliah's Peril. Johanan warns Gedaliah of his danger from Ishmael, another of the newly-submitted leaders (Jeremiah 41:1), alleged to be an agent of the king of Ammon (Jeremiah 27:3). Gedaliah refuses to believe this, or to avail himself of Johanan's offer to kill Ishmael.
Jeremiah 40:13-16
13 Moreover Johanan the son of Kareah, and all the captains of the forces that were in the fields, came to Gedaliah to Mizpah,
14 And said unto him, Dost thou certainly know that Baalis the king of the Ammonites hath sent Ishmael the son of Nethaniah to slayc thee? But Gedaliah the son of Ahikam believed them not.
15 Then Johanan the son of Kareah spake to Gedaliah in Mizpah secretly, saying, Let me go, I pray thee, and I will slay Ishmael the son of Nethaniah, and no man shall know it: wherefore should he slay thee, that all the Jews which are gathered unto thee should be scattered, and the remnant in Judah perish?
16 But Gedaliah the son of Ahikam said unto Johanan the son of Kareah, Thou shalt not do this thing: for thou speakest falsely of Ishmael.