Abu'd-Darda' reported that the Prophet, may Allah bless him and grant him peace, said, "Those who curse will be neither witnesses nor intercessors on the Day of Rising."

قَالَ النَّبِيُّ ﷺ إِنَّ اللَّعَّانِينَ لاَ يَكُونُونَ يَوْمَ الْقِيَامَةِ شُهَدَاءَ وَلا شُفَعَاءَ

Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "The true person must not be a curser."

قَالَ النَّبِيُّ ﷺ لاَ يَنْبَغِي لِلصِّدِّيقِ أَنْ يَكُونَ لَعَّانًا

Hudhayfa said, "People do not curse one another without that curse coming true."

تَلاَعَنَ قَوْمٌ قَطُّ إِلاَّ حُقَّ عَلَيْهِمُ اللَّعْنَةُ