Ali on Curses: Those who curse others are themselves cursed

‘Ubayd al-Kindi reported: Ali ibn Abi Talib, may Allah be pleased with him, said, “Those who curse others are themselves cursed.”

Source: al-Adab al-Mufrad 315

Grade: Hasan (fair) according to Al-Bukhari

عن عبيد الكندي قَالَ‏ قَالَ‏ علي بن أبي طالب رضي الله عنه‏ لُعِنَ اللَّعَّانُونَ

315 الأدب المفرد للبخاري باب ليس المؤمن بالطعان