'Seventy Sons' in the Bible

And Ahab had seventy sons in Samaria. And Jehu wrote letters, and sent to Samaria, unto the rulers of Jezreel, to the elders, and to them that brought up Ahab's children, saying,

Then he sent them a second letter, saying, If you are on my side, and if you will do my orders, come to me at Jezreel by this time tomorrow, with the heads of your master's sons. Now the king's seventy sons were with the great men of the town, who had the care of them.