Is it mustahabb to observe fasts in expiation for breaking an oath as the six days of Shawwaal?
Question

I have a question that has to do with swearing by Allah. I swore by Allah that I would not go to a certain place, but a week later I went to that place. I decided to fast three days during the six days of Shawwaal. It is it regarded as expiation for breaking the oath or what? May Allah reward you with good.
Praise be to Allah.Firstly: 
We would draw our brother’s attention to a number of important things before answering this question in particular. 
1.
The basic principle is that the Muslim should protect his oath and not swear oaths willy-nilly concerning matters that do not deserve to have the oath sworn by Allah concerning them. Allah says (interpretation of the meaning): “And protect your oaths (i.e. do not swear much)” [al-Maa’idah 5:89]. 
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have mercy on him) said: 
The basic principle is that one should not swear oaths a great deal, because Allah says (interpretation of the meaning): “And protect your oaths (i.e. do not swear much)” [al-Maa’idah 5:89]. Some of the scholars said, explaining the meaning of this verse: Do not swear a lot of oaths. And undoubtedly that is better and safer for the person and is more on the safe side.
Al-Sharh al-Mumti’, 15/117 
2.
As for the place that you swore not to go to, if it is a haraam place that it is not permissible for you to go to according to the laws of Allah, then it is obligatory for you to fulfil your oath and not to go there. If going to the place is obligatory -- such as upholding ties of kinship or visiting relatives -- then you must break your oath if your going there is obligatory, and it is mustahabb to break your oath if your going there is mustahabb. If going to that place is permissible, then see what is best for your religious and worldly affairs, and fear your Lord, and do that. If going there is better, then go there and offer expiation for breaking your oath; otherwise continue to refrain from going there. 
It was narrated that ‘Abd al-Rahmaan ibn Samurah (may Allah be pleased with him) said: the Messenger of Allah (blessings and peace of Allah be upon him) said: “If you swear an oath then decide that something else is better than it, then do that which is better and offer expiation for breaking your oath.” 
Narrated by al-Bukhaari (6343) and Muslim (1652). 
It was narrated from Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (blessings and peace of Allah be upon him) said: “Whoever swears an oath then sees that something else is better than it, let him do that and offer expiation for his oath.”
Narrated by Muslim (1650). 
In al-Mawsoo’ah al-Fiqhiyyah (8/63) it says: 
Fulfilling an oath means doing that which one swore to do. Allah says (interpretation of the meaning): “And fulfil the Covenant of Allaah (Bai‘ah: pledge for Islam) when you have covenanted, and break not the oaths after you have confirmed them — and indeed you have appointed Allaah your surety. Verily, Allaah knows what you do” [al-Nahl 16:91]. 
It is obligatory with regard to an oath to do something obligatory or to refrain from doing something haraam; so it is an oath to obey Allah which must be fulfilled by adhering to what one swore to do and it is haraam to break the oath. 
But if he swore to refrain from doing something obligatory or to do something haraam, then this is an oath to disobey Allah and must be broken. 
If he swore to do something naafil (supererogatory) such as a voluntary prayer or voluntary charity, then fulfilling the oath is recommended and breaking the oath is disliked. 
If he swore not to do something naafil, then the oath is makrooh and fulfilling it is makrooh, and the Sunnah is to break it. 
If it was an oath to do something permissible, then breaking the oath is permissible. The Messenger of Allah (blessings and peace of Allah be upon him) said: “If you swear an oath then decide that something else is better than it, then do that which is better and offer expiation for breaking your oath.” End quote. 
3.
Your decision to fast these three days for breaking your oath is not acceptable, unless you are unable to feed ten poor persons or to clothe them. The expiation for breaking an oath is feeding ten poor persons or clothing them, or freeing a slave; whoever cannot do that may fast three days. Allah says (interpretation of the meaning):
“Allaah will not punish you for what is unintentional in your oaths, but He will punish you for your deliberate oaths; for its expiation (a deliberate oath) feed ten Masaakeen (poor persons), on a scale of the average of that with which you feed your own families, or clothe them or manumit a slave. But whosoever cannot afford (that), then he should fast for three days. That is the expiation for the oaths when you have sworn. And protect your oaths (i.e. do not swear much). Thus Allaah makes clear to you His Ayaat (proofs, evidences, verses, lessons, signs, revelations, etc.) that you may be grateful”
[al-Maa’idah 5:89]. 
See also the answer to question number 45676. 
Secondly: 
With regard to your question about fasting in expiation for breaking the oath in Shawwaal and counting it as being among the six days of that month, what is narrated concerning the virtue of fasting these days along with Ramadan is that it is like observing obligatory fasts for a lifetime. So we say that if you are going to fast because you are unable to feed or clothe poor people, then do not count it as part of these six days of Shawwaal. It is not permissible to combine the intention of an obligatory deed and the intention of a naafil deed. Fasting in expiation in particular requires a separate intention, as is also the case with regard to fasting the six days of Shawwaal. Based on that, your fasting three days in expiation for breaking your oath cannot be counted as part of the six days of Shawwaal. 
The scholars of the Standing Committee were asked: 
Does fasting six days of Shawwaal and the day of ‘Ashoora’ and the day of ‘Arafah count as expiation for breaking an oath, if a person does not know the number of oaths he made. 
They replied: 
The expiation for breaking the oath is freeing a believing slave or feeding ten poor persons or clothing them. If a person is unable to do any of that then he may fast three days for each oath. 
With regard to your not knowing the number of oaths, you have to strive to make a rough estimate, then offer expiation for whatever oaths you broke, and that will be sufficient if Allah Wills. 
It is not acceptable to fast the day of Ashoora’, the day of ‘ ‘Arafah and six days of Shawwaal instead of fasting in expiation breaking your oath, unless you intend to fast these days on the basis that they are in expiation and not a voluntary fast. 
Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan 
Fataawa al-Lajnah al-Daa’imah, 23/37, 38 
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have mercy on him) was asked: 
A woman is saying that she swore an oath, and she wants to expiate for this oath by fasting three days. Is it permissible for her to fast them with the six days of Shawwaal, so that she will be fasting six days in total? 
He replied: 
Firstly: it is not permissible for a person who swore an oath to fast if he breaks it, unless he is unable to feed or clothe ten poor persons, or to free a slave, because Allah says (interpretation of the meaning): “for its expiation (a deliberate oath) feed ten Masaakeen (poor persons), on a scale of the average of that with which you feed your own families, or clothe them or manumit a slave. But whosoever cannot afford (that), then he should fast for three days. That is the expiation for the oaths when you have sworn” [al-Maa’idah 5:89]. It has become very widespread among many of the common folk who think that expiation for breaking an oath is fasting for three days both, but this is a mistake. Rather it is not permissible to fast except if the one who has broken his oath cannot afford to feed ten poor persons, or he can afford it but he cannot find poor people; in that case he may fast three consecutive days. 
Moreover, if it is permissible to combine these three days with any other fast; it is not acceptable to intend them as fasting some of the six days of Shawwaal, because these are two separate acts of worship and one of them cannot take the place of the other. Rather he may fast six days of Shawwaal, then fast three extra days in addition to the six days. 
Fataawa Noor ‘ala al-Darb, (/84, 85) 
It is not essential that the three days be consecutive. We have explained that in the answer to question number 12700. 
And Allah knows best.