John Wesley on 2 Kings 8:18

He walked - After his father's death. The daughter - Athaliah. This unequal marriage, though Jehoshaphat possibly designed it as a means of uniting the two kingdoms under one head, is here and elsewhere noted, as the cause both of the great wickedness of his posterity, and of those sore calamities which befel them. No good could be reasonably expected from such an union. Those that are ill matched are already half - ruined.