وَ«مُحَمَّدٌ نَبِيُّنَا».
Translation: Muhammad (peace and blessings be upon him) is our Prophet.
مُحَمَّدٌ: nominative mubtadaʾ, definite as a proper name.
نَبِيُّ: nominative khabar, the muḍāf in an iḍāfa.
نَا: bound pronoun functioning as genitive muḍāf ilayh.
«نَبِيُّنَا» is definite through iḍāfa, showing that a khabar is not invariably indefinite.