2 Kings 25:25

But it came about in the seventh month, that Ishmael the son of Nethaniah, the son of Elishama, of the royal family, came with ten men and struck Gedaliah down so that he died along with the Jews and the Chaldeans who were with him at Mizpah.

2 Kings 11:1

When Athaliah the mother of Ahaziah saw that her son was dead, she rose and destroyed all the royal offspring.

Jeremiah 40:15-15

Then Johanan the son of Kareah spoke secretly to Gedaliah in Mizpah, saying, "Let me go and kill Ishmael the son of Nethaniah, and not a man will know! Why should he take your life, so that all the Jews who are gathered to you would be scattered and the remnant of Judah would perish?"

Zechariah 7:5

"Say to all the people of the land and to the priests, 'When you fasted and mourned in the fifth and seventh months these seventy years, was it actually for Me that you fasted?

Zechariah 8:19

"Thus says the LORD of hosts, 'The fast of the fourth, the fast of the fifth, the fast of the seventh and the fast of the tenth months will become joy, gladness, and cheerful feasts for the house of Judah; so love truth and peace.'

Treasury of Scripture Knowledge

Summary

But it came to pass in the seventh month, that Ishmael the son of Nethaniah, the son of Elishama, of the seed royal, came, and ten men with him, and smote Gedaliah, that he died, and the Jews and the Chaldees that were with him at Mizpah.

General references

Bible References

Seventh

Zechariah 7:5
"Say to all the people of the land and to the priests, 'When you fasted and mourned in the fifth and seventh months these seventy years, was it actually for Me that you fasted?
Zechariah 8:19
"Thus says the LORD of hosts, 'The fast of the fourth, the fast of the fifth, the fast of the seventh and the fast of the tenth months will become joy, gladness, and cheerful feasts for the house of Judah; so love truth and peace.'

Ishmael

Jeremiah 40:15
Then Johanan the son of Kareah spoke secretly to Gedaliah in Mizpah, saying, "Let me go and kill Ishmael the son of Nethaniah, and not a man will know! Why should he take your life, so that all the Jews who are gathered to you would be scattered and the remnant of Judah would perish?"
Jeremiah 41:1
In the seventh month Ishmael the son of Nethaniah, the son of Elishama, of the royal family and one of the chief officers of the king, along with ten men, came to Mizpah to Gedaliah the son of Ahikam While they were eating bread together there in Mizpah,

Royal

2 Kings 11:1
When Athaliah the mother of Ahaziah saw that her son was dead, she rose and destroyed all the royal offspring.

General references

Jeremiah 41:3
Ishmael also struck down all the Jews who were with him, that is with Gedaliah at Mizpah, and the Chaldeans who were found there, the men of war.