56. Narrated Aboo Huraira (radhi Allaahu anhu) : The Prophet (Sallallaahu Alaihi Wasallam) said,
” Avoid the seven great destructive sins.” The people enquired, ” O Allaah’s Messenger (Sallallaahu Alaihi Wasallam) ! What are they ?” He said,
(1) To join others in worship along with Allaah;
(2) To practise sorcery ;
(3) To kill the life which Allaah has forbidden except for just cause ( according to Islaamic Law);
(4) To eat up Ribaa [usury];
(5) To eat up an orphan’s wealth;
(6) To show one’s back to the enemy and fleeing from the battlefield at the time of fighting, and
(7) To accuse chaste women, who never even think of anything touching chastity and are good believers.
[Saheeh Al-Bukhaari, Hadeet No. 28, Vol. 4]
Source : The Book of Belief : Chapter 36 -The mention (about) the great (major) sins and the greatest among them. Al-Lulu Wal-Marjan,Compiled by : Fuwad Abdul-Baqi,Translated by : Dr. Muhammad Muhsin Khan