John Chrysostom
What the Holy Spirit testified through the Prophet, saying, that He would cut off every male from the house of Ahab, and Jezebel, that Jehu the son of Nausi fulfilled, and received the promise that his children to the fourth generation should sit on the throne of Israel. As great a blessing then as was given upon the house of Ahab, so great a curse was given on the house of Joram, because of the wicked daughter of Ahab and Jezebel, that his sons to the fourth generation should be cut out of the number of the Kings. Thus his sin descended on his posterity as it had been written, I will visit the sins of the fathers upon the children unto the third and fourth generation. (Exod. 20:5.) Thus see how dangerous it is to marry with the seed of the ungodly.
But the order in the Book of Kings (2 Kings 23.) is different, thus namely; Josias begot Eliakim, afterwards called Joakim; Joakim begot Jechonias. But Joakim is not reckoned among the Kings in the genealogy, because God’s people had not set him on the throne, but Pharaoh by his might. For if it were just that only for their intermixture with the race of Ahab, three kings should be shut out of the number in the genealogy, was it not just that Joakim should be likewise shut out, whom Pharaoh had set up as king by hostile force? And thus Jechonias, who is the son of Joakim, and the grandson of Josiah, is reckoned among the kings as the son of Josiah, in place of his father who is omitted.