Sahih al-Bukhari 5973Book 78, Hadith 4
حَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، حَدَّثَنَا إِبْرَاهِيمُ بْنُ سَعْدٍ، عَنْ أَبِيهِ، عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو ـ رضى الله عنهما ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ مِنْ أَكْبَرِ الْكَبَائِرِ أَنْ يَلْعَنَ الرَّجُلُ وَالِدَيْهِ ". قِيلَ يَا رَسُولَ اللَّهِ وَكَيْفَ يَلْعَنُ الرَّجُلُ وَالِدَيْهِ قَالَ " يَسُبُّ الرَّجُلُ أَبَا الرَّجُلِ، فَيَسُبُّ أَبَاهُ، وَيَسُبُّ أَمَّهُ ".
Allah's Messenger (ﷺ) said. "It is one of the greatest sins that a man should curse his parents." It was asked (by the people), "O Allah's Messenger (ﷺ)! How does a man curse his parents?" The Prophet (ﷺ) said, "'The man abuses the father of another man and the latter abuses the father of the former and abuses his mother."