2 Kings 10:6-8

6Then Jehu wrote a second letter to them, saying, “If you are with me and will obey me, take the heads of your master’s sons, and come to me at Jezreel tomorrow about this time.” Now the [dead] king’s sons, seventy persons, were with the great men of the city, who were rearing them.

7When the letter came to them, they took the king’s sons and slaughtered them, seventy persons, and put their heads in baskets, and sent them to Jehu at Jezreel.

8When a messenger came and told him, “They have brought the heads of the king’s sons,” he said, “Put them in two heaps at the entrance of the city gate until morning.”