He may have written that regarding the time when Absalom tried to usurp the throne while David was ill and unable to handle the situation.
تَابَعَ مُوضِحًا :‏ « يَهْوَهُ يَسْنُدُهُ عَلَى فِرَاشِ ٱلسَّقَمِ .‏