Sahih Bukhari
Sahih Bukhari Volume 003, Book 043, Hadith Number 626.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 43. Oppressions
Narated By Abu Musa : The Prophet said, "A believer to another believer is like a building whose different parts enforce each other." The Prophet then clasped his hands with the fingers interlaced (while saying that).