Sahih Al Bukhari – Book of Dealing With Apostates

Volume 009, Book 084, Hadith Number 054. 
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Narrated By Abu Bakra

Razi Allah Anhu

: The Prophet

. said, "The biggest of the great sins are: To join others in worship with Allah, to be undutiful to one's parents, and to give a false witness." He repeated it thrice, or said, "…a false statement," and kept on repeating that warning till we wished he would stop saying it. (See Hadith No.7, Vol. 8) 

May Allah keep me away from these sins. Prayers requested.