[Machine] The Prophet ﷺ said: "Indeed, one of the greatest sins is for a person to curse his parents." They asked, "How can a person curse his parents?" He replied, "He curses someone's father, so that person retaliates by cursing his father, and he curses someone's mother, so that person retaliates by cursing his mother."

عَنِ النَّبِيِّ ﷺ قَالَ إِنَّ مِنْ أَكْبَرِالذَّنْبِ أَنْ يَسُبَّ الرَّجُلُ وَالِدَيْهِ قَالُوا وَكَيْفَ يَسُبُّ الرَّجُلُ وَالِدَيْهِ؟ قَالَ يَسُبُّ أَبَا الرَّجُلِ فَيَسُبُّ أَبَاهُ وَيَسُبُّ أُمَّهُ فَيَسُبُّ أُمَّهُ