Upon Jehu's arrival in Samaria, the city opens its gates to him without any resistance or protest. Once inside, he systematically slaughters all of Ahab's remaining supporters.
This brutal purge likely includes the very individuals who had previously executed Ahab's sons under Jehu's own orders. His motive for turning against these recent accomplices stems from either a deep lack of trust in them or a broader ambition to completely wipe out not only the royal family but the entire governmental structure that once served it [ביאור שטיינזלץ].
Through these sweeping actions, the house of Ahab is absolutely eradicated. This total destruction brings to pass the prophetic word of God that He had originally spoken to Elijah [ביאור שטיינזלץ].