أَحْسَنَ فِي عَيْنِهِ الْكُحْلُ
Aḥsana modifies the accusative rajulan; al-kuḥlu is a nominative overt subject governed exceptionally by aḥsana.
Opening interactive controls...
Why al-Kuḥlu Is Nominative
Ism al-Tafḍīl: Formation, Comparison, Agreement and Parsing
أَحْسَنَ فِي عَيْنِهِ الْكُحْلُ
Aḥsana modifies the accusative rajulan; al-kuḥlu is a nominative overt subject governed exceptionally by aḥsana.