In 2 Chronicles 22:2 it says Ahaziah was 42 when he became king, while in 2 Kings 8:26 it says he was 22. In a book by a Rabbi Moshe Eisemann, I saw an interesting explanation for this, which I understand and seems logical. It says the Chronicles entry is 42 years from when Jehoshaphat married the daughter of Omri. He states that Radak and Rahsi both compute this 42 years from Scripture. Their commentaries on these books are not available in English, however. Can you please tell me how the 42 years is computed? What verses allow us to know that the marriage was 42 years earlier? Is there possibly some English source that I can read that will explain it? Thank you!

It’s quite simple: the Radak (Kings 8, 26) explains that from the time that Yehoram fell ill with his acute intestinal problem, he took his son Achazyahu to help him rule. So Achazyahu ruled 20 years during his father’s lifetime (from the age of 22), and an additional one year where he ruled alone (from the age of 42), after his father’s death. Accordingly, the Bible also only counts 8 years of Yehoram’s kingdom, for these are just the years which he ruled alone (without his son), and not the 20 years where his son helped him rule during his lifetime.