Sahih Muslim
The Book Pertaining to the Excellent Qualities of the Holy Prophet (may Peace be upon them) and His Companions (Kitab Al-Fadail)
Book Number: 030 / Hadith Number: 5677
Jabir reported Allah's Messenger (may peace be upon him) as saying: The similitude of mine and that of the Apostles is like that of a person who built a house and he completed it and made it perfect but for the space of a brick. People entered therein and they were surprised at it and said: Had there been a brick (it would have been complete in all respects). Allah's Messenger (may peace be upon him) said: I am that place where the brick (completing the building is to be placed), and I have come to finalise the chain of Apostles.