In the seventh month, Ishmael son of Nethaniah son of Elishama, of the royal family, one of the chief officers of the king, came with ten men to Gedaliah son of Ahikam, at Mizpah. As they ate bread together there at Mizpah,
Ishmael son of Nethaniah and the ten men with him got up and struck down Gedaliah son of Ahikam son of Shaphan with the sword and killed him, because the king of Babylon had appointed him governor in the land.
Ishmael also killed all the Judeans who were with Gedaliah at Mizpah, and the Chaldean soldiers who happened to be there.
On the day after the murder of Gedaliah, before anyone knew of it,
eighty men arrived from Shechem and Shiloh and Samaria, with their beards shaved and their clothes torn, and their bodies gashed, bringing grain offerings and incense to present at the temple of the Lord.
And Ishmael son of Nethaniah came out from Mizpah to meet them, weeping as he came. As he met them, he said to them, "Come to Gedaliah son of Ahikam."
When they reached the middle of the city, Ishmael son of Nethaniah and the men with him slaughtered them, and threw them into a cistern.
References for Jeremiah 41:7
But there were ten men among them who said to Ishmael, "Do not kill us, for we have stores of wheat, barley, oil, and honey hidden in the fields." So he refrained, and did not kill them along with their companions.
Now the cistern into which Ishmael had thrown all the bodies of the men whom he had struck down was the large cistern that King Asa had made for defense against King Baasha of Israel; Ishmael son of Nethaniah filled that cistern with those whom he had killed.
References for Jeremiah 41:9