تَصْلَىٰ نَارًا حَامِيَةًۭ
Sentence structure
تَصْلَىٰ has the preceding faces as its understood subject. نَارًا is the object and حَامِيَةً its accusative adjective.
Ayah summary
They will enter a blazing fire.
تَصْلَىٰ — They will burn
Grammar: A third-person feminine-singular indicative imperfect with an understood subject referring to the faces.
نَارًا — (in) a Fire
Grammar: An indefinite feminine-singular accusative object of تَصْلَىٰ.
حَامِيَةًۭ — intensely hot
Grammar: An indefinite feminine-singular accusative adjective of نَارًا.