דברי הימים ב, פרק כ״ב, פסוק ח׳

Jehu's campaign of destruction was sweeping and absolute, targeting not only the direct family of Ahab but also their allies and supporters. During the time he was executing a sentence of death upon Ahab's household [מצודת דוד, ביאור שטיינזלץ], his path crossed with a group from the southern kingdom. While on the road, Jehu encountered the officers of Judah and the relatives of Ahaziah, the king of Judah [מלבי"ם, ביאור שטיינזלץ].

These relatives were specifically the sons of Ahaziah's brothers, rather than his actual brothers. This careful distinction is necessary because all of Ahaziah's own brothers had already been killed earlier, during the reign of their father, Jehoram [רש"י, מלבי"ם]. Understanding this detail also clarifies a parallel account in the Book of Kings, which mentions Jehu finding Ahaziah's brothers. The commentators explain that the earlier account is actually referring to his nephews, exactly as detailed in this historical record [רד"ק, מלבי"ם].

These men were under the direct service of Ahaziah [מצודת דוד] and were traveling to assist him and the royal family of Israel [רד"ק]. Since the king of Judah was a descendant of Ahab himself and a close ally of Israel's king, Jehu viewed his entourage as part of the same corrupt network. Without hesitation, Jehu killed them, ensuring the complete elimination of anyone tied to or supporting the house of Ahab [ביאור שטיינזלץ].