جامع الترمذي

Narrated 'Abdur-Rahman bin Abi Bakrah: from his father that the Messenger of Allah (ﷺ) said: "Shall I not narrate to you about the worst of the major sins?" They said: "Of course O Messenger of Allah!" He said: "Associating others with Allah and disobeying the parents." He said: "And he sat reclining and said: 'The false testimony.' Or he said: 'The false statement.'" He said: "So the Messenger of Allah (ﷺ) would not stop saying it until we said (to ourselves): 'If he would only stop.'"