2 Kings 10:5-7

ISV(i) 5 So the household overseer and the city supervisor, along with the elders and the children’s guardians, sent word to Jehu, telling him, “We will serve you and do everything you ask. We won’t set up a king, so do what you want to do.”
6 But Jehu wrote them another letter: “If you’re loyal to me, and if you intend to obey my commands, then bring the heads of your master’s sons and meet me in Jezreel about this time tomorrow.”
Now the king’s sons, totaling 70 men, were living with the leading men of the city, who were their guardians. 7 When the letter from Jehu arrived, the city leaders arrested the king’s sons, slaughtered all 70 of them, put their heads in baskets, and sent them to Jehu at Jezreel.