Expressing determination to do something without mentioning the Name of Allaah
8-4-2014 | IslamWeb
Question:
Assalamu alaikum, If a person makes an oath to refrain from something, but later does that activity and gets some benefit from it, is that benefit haram for him? If so, then if he pays Kaffara for it, will that become halal? And if a person makes an oath not to do something, but later wishes to do so, how many times does he have to pay Kaffara? Only once or for every time he does that? I was insulted once in a forum and out of anger (not blind anger, I was able to reason) I said, "I will never post here again". Is that considered a promise or an oath? I later understood that not everyone there is rude and joined that forum again. Have I done anything wrong? I got some benefits from that forum as well (earned knowledge, got advice and made friends). Is that benefit haram for me? What should I do now? Thanks.
Answer:
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 
is His slave and Messenger.
Asna Al-Mataalib reads: “If a person makes an oath to do or to abandon something permissible ... like entering a house, or wearing a kind of clothes, or eating a kind of food or not eating it, then it is desirable for him to fulfill it, as Allaah says (what means): {….and do not break oaths after their confirmation…} [Quran 16:91], because it involves glorifying Allaah; An-Nawawi said in Rawdhat At-Taalibeen: “We conclude from what we have mentioned that the oath does not change the state of that about which the oath has been made; whether it is obligatory or prohibited or recommended or disliked or permissible.” [End of quote]
We have explained the expiation of oaths in Fatwa 82135.
If a person makes an oath not to go to the market, for example, and then he intends to go, then an expiation is not required just because he intended to go; rather, an expiation is only required if he really goes to the market, and it is only required once unless one intends to expiate every time he goes. The repetition of expiation or its non-repetition depends on the wording of the oath and the intention of the one who had made it; therefore, if the person who made the oath did not say words that indicate making expiation every time he does that act, like saying "every time I do it", then the expiation is not repeated every time he does what he had made the oath about. For more benefit, please refer to Fataawa 138168 and 119549.
What you said: “I will never post here again” is not considered an oath because you did not swear by one of the Names or Attributes of Allaah; Kashshaaf Al-Qinaa’ reads: “The oath that requires expiation if one breaks it, is the oath in which he says: 'I swear by Allaah, or by one of His Attributes, like saying: I swear by Ar-Rahmaan ...” . Therefore, you are not required to do anything if you post again in the forum. For more benefit, please refer to Fatwa 234937.
Moreover, what you have benefitted from that forum does not become forbidden for you, if it is in itself permissible.
Finally, we have noticed from this question and your previous questions that you are affected by some sort of Waswasah (obsessive whisperings), so we advise you to fear Allaah and not get carried away with those whisperings and not ask many questions that are caused by them.
Allaah Knows best.