مَا كَانَ مُحَمَّدٌ أَبَا أَحَدٍ مِنْ رِجَالِكُمْ وَلَٰكِنْ رَسُولَ اللَّهِ وَخَاتَمَ النَّبِيِّينَ وَكَانَ اللَّهُ بِكُلِّ شَيْءٍ عَلِيمًا.
Muhammad ﷺ is not the father of any of your men, but is Allah’s Messenger and the Seal of the Prophets, and Allah has full knowledge of everything. (Al-Aḥzāb 33:40)
Wa-khātam al-nabiyyīn is an explicit declaration of the finality of prophethood. It affirms both his messengership and his position as the last prophet.