And when the letter arrived, they took the sons of the king and slaughtered all seventy of them. They put their heads in baskets and sent them to Jehu at Jezreel.

Judges 9:5
He went to his father's house in Ophrah, and on one stone murdered his seventy brothers, the sons of Jerubbaal. But Jotham, the youngest son of Jerubbaal, survived, because he hid himself.

2 Kings 10:6
Then Jehu wrote them a second letter and said: "If you are on my side, and if you will obey me, then bring the heads of your master's sons to me at Jezreel by this time tomorrow." Now the sons of the king, seventy in all, were being brought up by the leading men of the city.

2 Kings 10:8
When the messenger arrived, he told Jehu, "They have brought the heads of the sons of the king." And Jehu ordered, "Pile them in two heaps at the entrance of the gate until morning."

2 Kings 11:1
When Athaliah the mother of Ahaziah saw that her son was dead, she proceeded to annihilate all the royal heirs.

And it came to pass, when the letter came to them, that they took the king's sons, and slew seventy persons, and put their heads in baskets, and sent him them to Jezreel.