Jeremiah 41:5-9

5that eighty men came from Shechem, from Shiloh, and from Samaria with their beards shaved off and their clothes torn and their bodies cut, carrying in their hands grain offerings and incense to present at the [site of the] house of the Lord [in Jerusalem].

6Then Ishmael the son of Nethaniah went out from Mizpah to meet them, weeping [false tears] as he went. As he met them, he said to them, “Come to Gedaliah the son of Ahikam!”

7Yet when they came into the city, Ishmael the son of Nethaniah and the men who were with him slaughtered them and threw them into the cistern (underground water reservoir).

8But ten men who were among them said to Ishmael, “Do not kill us! We have stores of wheat and barley and oil and honey hidden in the field.” So he stopped and did not kill them along with their companions.

9Now the cistern into which Ishmael had thrown all the corpses of the men whom he had killed along with Gedaliah was the one which King Asa [of Judah] had made [about three hundred years earlier] on account of King Baasha of Israel [believing that Baasha would lay siege to Mizpah]. Ishmael the son of Nethaniah filled it with [the bodies of] those who were killed.