2 Kings 10:6-7

6Jehu responded with a second letter: “If you are on my side and are going to obey me, bring the heads of your master’s sons to me at Jezreel by this time tomorrow.” Now the seventy sons of the king were being cared for by the leaders of Samaria, where they had been raised since childhood.

7When the letter arrived, the leaders killed all seventy of the king’s sons. They placed their heads in baskets and presented them to Jehu at Jezreel.