Sahih Muslim | Book 30 | Hadith Number 5673

Narrated by Abu Huraira
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: The similitude of mine and that of the Apostles (before me) is that of a person who constructed a building and he built it fine and well and the people went round it saying: Never have we seen a building more imposing than this, but for one brick, and I am that brick (with which you give the finishing touch to the building).