(225) لاَّ يُؤَاخِذُكُمُ اللّهُ بِاللَّغْوِ فِيَ أَيْمَانِكُمْ وَلَكِن يُؤَاخِذُكُم بِمَا كَسَبَتْ قُلُوبُكُمْ وَاللّهُ غَفُورٌ حَلِيمٌ
225. " Allah will not hold you liable for thoughtlessness in your oaths, but He will hold you liable for what your hearts have incurred; and Allah is Forgiving, Forbearing."
The oaths which have been taken thoughtlessly, carelessly, or at the time of anger and with no intention or will; or the oaths taken because of loquaciousness and in hurry-scurry speakings, are not legally valuable.
The liability to an oath is payable only when it is taken deliberately, in a normal situation, and by the Holy Name of Allah for a useful affair. This sort of oath is religiously obligatory to be executed. Therefore, breaking it is unlawful and the atonement of which is detailed in Sura Al-Ma'idah.(1) So, the expiation of it is the feeding of ten indigents, or a suitable clothing given to them, or the freeing of a slave; but if the one finds the possibility of none of them then, he/she should observe the fast for three days.
The responsibility of man depends on his will and decisions for what he elects. Allah forgives the faults of His servants which have been issued from them in some abnormal conditions.
(1) Sura Al-Ma'idah, No. 5, verse 89