Anas (RA) narrated from the Apostle (peace be upon him) about the major sins. He (the Holy Prophet) observed: Associating anyone with Allah, disobedience to parents, killing a person and false utterance.
(Sahih Muslim, Book 1, Hadith 166)
Hadith on Faith: The major sins and the most serious of them (Sahih Muslim) (islamicity.org)
