Al-Baqarah - 2:225

لاَّ يُؤَاخِذُكُمُ اللّهُ بِاللَّغْوِ فِيَ أَيْمَانِكُمْ وَلَكِن يُؤَاخِذُكُم بِمَا كَسَبَتْ قُلُوبُكُمْ وَاللّهُ غَفُورٌ حَلِيمٌ
[2:225]
Allah does not call you to account for what is vain in your oaths, but He will call you to account for what your hearts have earned, and Allah is Forgiving, Forbearing.
Allah will not call you to account for thoughtlessness in your oaths, but for the intention in your hearts; and He is Oft-forgiving, Most Forbearing.
Allah will not take you to task for that which is unintentional in your oaths. But He will take you to task for that which your hearts have garnered. Allah is Forgiving, Clement.