2 Samuel 19:2
And the victory that day was turned into mourning unto all the people: for the people heard say that day how the king was grieved for his son.
Cross-reference
2 Samuel 14:1
Historical context
In 2 Samuel 14:1, Joab knew David's heart was toward Absalom — explaining why David's grief was so intense and affected the victory celebration.
Proverbs 16:15
Contrast
Proverbs 16:15 says a king's favor brings life — contrasting sharply with David's grief turning victory into mourning for the people.