كتاب الفضائل
Read the English translation first, with the original Arabic directly underneath.
Abu Hurairh reported Allah's Messenger (ﷺ) as saying:
The similitude of mine and that of the Messengers before me is that of a person who built a house quite imposing and beautiful, but for one brick in one of its corners. People would go round it, appreciating the building, but saying: Why has the brick not been fixed here? He said: I am that brick and I am the last of the Messengers.
مَثَلِي وَمَثَلُ الأَنْبِيَاءِ مِنْ قَبْلِي كَمَثَلِ رَجُلٍ بَنَى بُنْيَانًا فَأَحْسَنَهُ وَأَجْمَلَهُ إِلاَّ مَوْضِعَ لَبِنَةٍ مِنْ زَاوِيَةٍ مِنْ زَوَايَاهُ فَجَعَلَ النَّاسُ يَطُوفُونَ بِهِ وَيَعْجَبُونَ لَهُ وَيَقُولُونَ هَلاَّ وُضِعَتْ هَذِهِ اللَّبِنَةُ - قَالَ - فَأَنَا اللَّبِنَةُ وَأَنَا خَاتَمُ النَّبِيِّينَ