Cursing in Islam is prohibited

Muslims should neither curse nor imprecate each other with words such as, ‘May the Curse of Allah be upon you,’ or ‘I wish you to burn in Hell-fire,’ etc.Narrated Samurah Ibn Jundub (radhi allahu anhu), ‘Allah’s Messenger (sallallahu aliahi wa-sallam) said,

‘Do not curse one another, invoking curse of Allah or Wrath of Allah or the fire of Hell’ [Abu Dawood, at-Tirmidhee]

To curse a Muslim is akin to killing him. Allah’s Messenger (sallallahu aliahi wa-sallam) said, Cursing a believer is like murdering him.’ [Agreed upon]

The act of cursing is such that one who does it can himself become a recipient of it.

Narrated Abu Darda (radhi allahu anhu),

Allah’s Messenger (sallallahu aliahi wa-sallam) said, When a person curses (La’nah; to ask that something be deprived of Allah’s Mercy) somebody or something, the curse goes up to the heaven and the gates of the heaven are closed. Then it comes down to the earth and its gates are closed. Then it turns right and left, and if it does not find an entrance to go anywhere, it returns to the person or thing that was cursed, if he or it deserves to be cursed; otherwise, it returns to the person, who uttered it.’ [Abu Dawood] Allah’s Messenger (sallallahu aliahi wa-sallam) also warned, ‘Those who frequently resort to cursing would neither be accepted as witnesses nor as intercessors on the Day of Resurrection’ [Saheeh Muslim]

It is not allowed to curse, disgrace or humiliate even a sinner because in doing so, one helps the Shaytan, who is avowed to disgrace and humiliate Muslims before Allah. Narrated Abu Hurayrah (radhi allahu anhu), ‘A drunkard was brought to the Prophet (sallallahu aliahi wa-sallam). He (r) said, ‘Give him a beating.’ Then some beat him with their hands, some with their shoes, and some with (a folded) piece of cloth. When he left, someone said to him, ‘May Allah disgrace you!‘ The Prophet (sallallahu aliahi wa-sallam) said, ‘Do not help

Shaytan overcome him by uttering such words’ [Saheeh al-Bukharee]

Moreover, it is incorrect to curse a sinner because perhaps, the person may have sought Istagfar (seek forgiveness for one’s sins) and Allah, the All-Forgiving, may have forgiven the person for his transgression. It is related in Saheeh Muslim that during the time of Allah’s Messenger (sallallahu aliahi wa-sallam), when a woman was being punished for the sin of adultery, her blood spurted upon Khalid Ibn Waleed (radhi allahu anhu), who swore at her. Thereupon, the Prophet (sallallahu aliahi wa-sallam) said, ‘Khalid, be gentle. By Him, in Whose Hand is my life, she has made such a repentance that even if a wrongful tax collector were to repent, he would have been forgiven.’ He (sallallahu aliahi wa-sallam) then prayed over her and she was buried. Therefore, the right conduct would be to pray for his or her guidance and refrain from any critique, cursing or humiliation.

Even the deceased Muslims should not be censured or condemned for their wrongdoings, for, they have reached their end and they are receiving the return of their deeds in the Hereafter. Aa’isha (radhi allahu anha) narrated, ‘The Messenger of Allah (sallallahu aliahi wa-sallam) said, ‘Do not abuse the dead, because they have attained that which they had forwarded (i.e., their deeds, good or bad).’ [Saheeh al-Bukharee]