Al-Adab Al-Mufrad #15

Abu Bakra reported that the Messenger of Allah, may Allah bless him and grant him peace, said, "Shall I tell you which is the worst of the major wrong actions?" "Yes, Messenger of Allah," they replied. He said, "Associating something else with Allah and disobeying parents." He had been reclining but then he sat up and said, "and false witness." Abu Bakra said, "He continued to repeat it until I said, 'Is he never going to stop?'"