Narrated Abu Bakra:Allah's Messenger (ﷺ) said thrice, "Shall I not inform you of the biggest of the great sins?" We said, "Yes, O Allah's Messenger (ﷺ)" He said, "To join partners in worship with Allah: to be undutiful to one's parents." The Prophet (ﷺ) sat up after he had been reclining and added, "And I warn you against giving forged statement and a false witness; I warn you against giving a forged statement and a false witness." The Prophet kept on saying that warning till we thought that he would not stop.
حَدَّثَنِي إِسْحَاقُ، حَدَّثَنَا خَالِدٌ الْوَاسِطِيُّ، عَنِ الْجُرَيْرِيِّ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي بَكْرَةَ، عَنْ أَبِيهِ ـ رضى الله عنه ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَلاَ أُنَبِّئُكُمْ بِأَكْبَرِ الْكَبَائِرِ ". قُلْنَا بَلَى يَا رَسُولَ اللَّهِ. قَالَ " الإِشْرَاكُ بِاللَّهِ، وَعُقُوقُ الْوَالِدَيْنِ ". وَكَانَ مُتَّكِئًا فَجَلَسَ فَقَالَ " أَلاَ وَقَوْلُ الزُّورِ وَشَهَادَةُ الزُّورِ، أَلاَ وَقَوْلُ الزُّورِ وَشَهَادَةُ الزُّورِ ". فَمَا زَالَ يَقُولُهَا حَتَّى قُلْتُ لاَ يَسْكُتُ.
Bukhari
Good Manners and Form (Al-Adab) • Hadith 7