صَارَ الْمَاءُ ثَلْجًا
Translation: The water became ice.
صَارَ: past incomplete verb.
الْمَاءُ: nominative ism ṣāra, visible ḍamma.
ثَلْجًا: accusative khabar ṣāra, visible fatḥa.
«ثَلْجًا» does not name a separate object acted upon; it states the water’s resulting condition, so it is khabar ṣāra.