From Sahih Bukhari (Hadith 3535):
Narrated Abu Huraira:Allah's Messenger (ﷺ) said, "My similitude in comparison with the other prophets before me, is that of a man who has built a house nicely and beautifully, except for a place of one brick in a corner. The people go about it and wonder at its beauty, but say: 'Would that this brick be put in its place!' So I am that brick, and I am the last of the Prophets
Reference: Bukhari 3535