Albert Barnes Commentary 1 Kings 20:43

"And the king of Israel went to his house heavy and displeased, and came to Samaria." — 1 Kings 20:43 (ASV)

Heavy and displeased - Rather, this means “sullen and angry,” as the marginal reference also notes. This was not repentance, such as what followed Elijah’s warning in 1 Kings 21:27. He was not acknowledging the justice of his sentence, but was full of sullenness and suppressed anger.