Matthew Henry Commentary 2 Chronicles 21:12-20

"And there came a writing to him from Elijah the prophet, saying, Thus saith Jehovah, the God of David thy father, Because thou hast not walked in the ways of Jehoshaphat thy father, nor in the ways of Asa king of Judah, but hast walked in the way of the kings of Israel, and hast made Judah and the inhabitants of Jerusalem to play the harlot, like as the house of Ahab did, and also hast slain thy brethren of thy father`s house, who were better than thyself: behold, Jehovah will smite with a great plague thy people, and thy children, and thy wives, and all thy substance; and thou shalt have great sickness by disease of thy bowels, until thy bowels fall out by reason of the sickness, day by day. And Jehovah stirred up against Jehoram the spirit of the Philistines, and of the Arabians that are beside the Ethiopians: and they came up against Judah, and brake into it, and carried away all the substance that was found in the king`s house, and his sons also, and his wives; so that there was never a son left him, save Jehoahaz, the youngest of his sons. And after all this Jehovah smote him in his bowels with an incurable disease. And it came to pass, in process of time, at the end of two years, that his bowels fell out by reason of his sickness, and he died of sore diseases. And his people made no burning for him, like the burning of his fathers. Thirty and two years old was he when he began to reign, and he reigned in Jerusalem eight years: and he departed without being desired; and they buried him in the city of David, but not in the sepulchres of the kings." — 2 Chronicles 21:12-20 (ASV)

A warning from God was sent to Jehoram. The Spirit of prophecy might have directed Elijah to prepare this writing in foresight of Jehoram's crimes. He was plainly told that his sin would certainly ruin him. But it is no wonder that sinners are not frightened from sin and moved to repentance by the threats of misery in another world, when even the certainty of misery in this world—the loss of their estates and the ruin of their health—will not restrain them from their vicious ways.

See Jehoram here, stripped of all his comforts. Thus God plainly showed that the controversy was with him and his house. He had slain all his brothers to strengthen himself; now, all his sons were slain but one. David's house was not to be completely destroyed, like those of Israel's kings, because a blessing was in it: that of the Messiah.

Good people may be afflicted with diseases; but for them, these are fatherly discipline, and with the support of divine comfort, the soul can be at peace, even when the body is in pain. To be sick and poor, sick and solitary, but especially to be sick and in sin, sick and under God's curse, sick and without grace to bear it, is a most deplorable situation. Wickedness and ungodliness make people despicable, even in the eyes of those who have little religion.