Then they took him and threw him into the cistern. (Now the cistern was empty; ¹  there was no water in it.)

Now the cistern where Ishmael threw all the dead bodies of those he had killed was a large one ¹  that King Asa had constructed as part of his defenses against King Baasha of Israel. ²  Ishmael son of Nethaniah filled it with dead bodies. ³