Abdur-Rahman bin Abi Bakrah narrated from his father that the Messenger of Allah (s.a.w) said:"Shall I not inform you of the greatest of the major sins?" They said: "Of course O Messenger of Allah(s.a.w)!" He said: "Shirk with Allah disobeying parents, and false testimony." Or: "False speech" He said: "So the Messenger of Allah(s.a.w) would not stop saying it until we said ( to ourselves): 'I wish he would be quiet

English translation · Jami' at-Tirmidhi