Sahih Bukhari
Sahih Bukhari Volume 004, Book 055, Hadith Number 638.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 55. Prophets
Narated By 'Abdullah : When the Verse: 'Those who believe and mix not their belief with wrong." was revealed, the companions of the Prophet said, "Who amongst us has not mixed his belief with wrong?" Then Allah revealed: "Join none in worship with Allah, Verily joining others in worship with Allah is a great wrong indeed."