Abu Huraira (radiAllahu ‘anhu) reported: the Prophet (Sallallaahu Alayhi Wasallam) said,
“Avoid the seven serious sins (As-sa’ Al-Mubiqat)”
People asked, ‘What are they?’
The Prophet Peace and Blessing upon him) replied,
“Shirk (polytheism), sihr (sorcery), unlawful killing of a person, living on money from usury, usurping an orphan’s wealth, retreat at the time of Jihad, and accusing innocent married women of fornication”.
Al-Bukhari (in FathAl-Bari 5/393) and Muslim (in Sharh An-Nawawi 2/83)