Sayyidina Abu Bakrah (RA) reported that Allah’s Messenger asked, ‘Shall I not inform you of the great of the gravest of sins?” They said, “Of course, 0 Messenger of Allah!” He said, “Joining partner with Allah and disobedience to parents.”He then sat straight though he had been reclining before and said, “False testimony.” or he said, “False speech.” He did not cease to say that till they hoped that he would pause.
[Bukhari 2654, Muslim 87]