Is it permissible to curse Satan? Is it permissible to use abusive language when joking with friends?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.

Muslims are neither commanded to nor prohibited from cursing Satan, since Satan has already been cursed. Allaah The Almighty, cursed him, Saying (what means):

• {And indeed, upon you is the curse until the Day of Recompense.} [Quran 15:35]
• {They call upon instead of Him none but female [deities], and they [actually] call upon none but a rebellious Satan. Whom Allaah has cursed.} [Quran 4:117-118]

Therefore, there is no benefit in being occupied with cursing Satan, especially since this does not foil the plots and whispers of Satan. On the contrary, it might increase Satan’s pride. In a Hadeeth (narration) on the authority of the father of Abu Al-Maleeh the Prophet forbade him from saying, "Fie, Satan!" and told him that it increases Satan's pride when he hears it. He ordered him to say, "Bismillaah" (In the Name of Allaah), for this makes him as small as a fly. [Ahmad] [Al-'Arnaa'oot: Saheeh (authentic)]

At-Tahaawi stated that the Prophet ordered us to mention the Name of Allaah when we stumble, so that Satan will not think that he has caused it. For this reason, Allaah The Almighty commanded us to seek refuge with Him from Satan, for this is the only way to get rid of his plots and whispers. He, The Almighty, Says (what means):

• {And if there comes to you from Satan an evil suggestion, then seek refuge in Allaah. Indeed, He is the Hearing, the Knowing.} [Quran 41:36]
• {So when you recite the Quran, [first] seek refuge in Allaah from Satan, the expelled [from His mercy].} [Quran 16:98]

Also the Prophet did not instruct a person whose prayer is hindered by Satan to curse him. Instead, he instructed Muslims to seek refuge with Allaah The Almighty. In a Hadeeth on the authority of ‘Uthmaan ibn Abi Al-‘Aas, the Prophet instructed a Muslim whose prayer was interrupted by devilish whispers to seek refuge with Allaah The Almighty from the devil and to spit, with moist breath, three times on his left. [Muslim]

Satan's power over humans consists of his tempting whispers to them, casting evil into their hearts and making them forget what benefits them. For example, Allaah The Almighty quoted the companion of Moosa (Moses ) as saying (what means):

• {Indeed, I forgot [there] the fish. And none made me forget it except Satan - that I should mention it. And it took its course into the sea amazingly.} [Quran 18:63]

Also in the story of Yoosuf (Joseph) Allaah The Almighty Says (what means): {But Satan made him forget the mention [to] his master, and Yoosuf (Joseph) remained in prison several years.} [Quran 12:42]

As for using abusive language, this is prohibited whether used seriously or in jest, and it is not the habit of believers to use these words. The Prophet mentioned that a believer is not a slanderer or foul-mouthed; he does not curse or utter obscenities. [Abu Daawood] [Al-'Albaani: Saheeh (authentic)]

He also mentioned that a man may commit a major sin by cursing his own parents. The Prophet explained that this happens when a man curses the parent of another man -- the other man will curse the parents of the one who insulted him in return. [Al-Bukhari and Muslim]

Therefore, it is obligatory for Muslims to refrain from every evil word and to speak only what brings them benefit in this life and the Hereafter. Let every Muslim be fully aware that every word he speaks is recorded, and they will be held accountable for every word uttered. Allaah The Almighty Says (what means):

• {Man does not utter any word except that with him is an observer prepared [to record].} [Quran 50:18]
• {Or do they think that We hear not their secrets and their private conversations? Yes, [We do], and Our messengers are with them recording.} [Quran 43:80]

As for slander, if a person slanders a chaste woman or man, accusing them of adultery or fornication, and fails to prove this by presenting four eye-witnesses, this person will deserve the punishment prescribed by the Sharee‘ah (Islamic law), whether done seriously or in jest. Allaah The Almighty Says (what means):

• {Indeed, those who [falsely] accuse chaste, unaware and believing women are cursed in this world and the Hereafter; and they will have a great punishment.} [Quran 24:23]
• {And those who accuse chaste women and then do not produce four witnesses - lash them with eighty lashes and do not accept from them testimony ever after. And those are the defiantly disobedient.} [Quran 24:4]

In conclusion, a Muslim must be careful with what he says – one careless word could cause a man to suffer misery in this life and in the Hereafter. The Prophet warned Muslims that a man might say a word heedlessly that calls for him to be thrown in Hell for a distance that equals the distance between East and West. [Al-Bukhari]

May Allaah The Almighty save us and other Muslims as well.

Allaah Knows best.