Tirmidhi Book 27, Hadith 1902

حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنِ ابْنِ الْهَادِ، عَنْ سَعْدِ بْنِ إِبْرَاهِيمَ، عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، قَالَ:‏‏‏‏ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ:‏‏‏‏ مِنَ الْكَبَائِرِ أَنْ يَشْتُمَ الرَّجُلُ وَالِدَيْهِ ، ‏‏‏‏‏‏قَالُوا:‏‏‏‏ يَا رَسُولَ اللَّهِ، ‏‏‏‏‏‏وَهَلْ يَشْتُمُ الرَّجُلُ وَالِدَيْهِ ؟ قَالَ:‏‏‏‏ نَعَمْ، ‏‏‏‏‏‏يَسُبُّ أَبَا الرَّجُلِ فَيَشْتُمُ أَبَاهُ وَيَشْتُمُ أُمَّهُ فَيَسُبُّ أُمَّهُ ، ‏‏‏‏‏‏قَالَ أَبُو عِيسَى:‏‏‏‏ هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ.

Abdullah bin 'Amr narrated that : the Messenger of Allah said: It is among the greatest of sins that a man should curse his parents. They said: O Messenger of Allah! Does a man curse his parents? He said: Yes. He verbally abuses the father of a man, who in turn, verbally abuses his father, and he (retaliates and) curses his mother , so he curses his mother.