What does 2 Kings 10:1 mean?

Ahab had seventy sons living in Samaria. Jehu wrote letters and sent them to the city’s leaders, elders, and the guardians of Ahab’s children. The letters said: 2 Kings 10:1 - Modern Text Bible

(Jehu turns his attention to wiping out the rest of Ahab’s family, sending a message to those in charge of the king’s sons.)