Abu Bakrah (May Allah be pleased with him) reported: The Messenger of Allah ﷺ said, "Shall I not inform you of one of the gravest of the cardinal sins?" We said: "Yes, O Messenger of Allah!" He ﷺ said, "To join others as partners with Allah in worship and to be undutiful to one's parents". The Messenger of Allah ﷺ sat up from his reclining position (in order to stress the importance of what he was going to say) and added, "I warn you making a false statement and giving a false testimony. I warn you against making a false statement and giving a false testimony". The Messenger of Allah ﷺ kept on repeating this (warning) till we wished he should stop. Al- Bukhari and Muslim