Narrated 'Aishah (RA) regarding the saying of Allah the Most High:

"Allah will not punish you for what is unintentional in your oaths (5:89)." She said: It (was sent down about such phrases as) a person's sayying: 'No, by Allah' and 'Yes, by Allah.' [al-Bukhari reported it (Mauquf, i.e. as a saying of 'Aishah). Abu Dawud reported it as Marfu' (attributed to the Prophet).]

وَعَنْ عَائِشَةَ رَضِيَ اَللَّهُ عَنْهَا { فِي قَوْلِهِ تَعَالَى: ﴿ لَا يُؤَاخِذُكُمُ اَللَّهُ بِاللَّغْوِ فِي أَيْمَانِكُمْ ﴾ [1]‏ قَالَتْ: هُوَ قَوْلُ اَلرَّجُلِ: لَا وَاَللَّهِ.‏ بَلَى وَاَللَّهِ } أَخْرَجَهُ اَلْبُخَارِيُّ [2]‏ .‏ وَأَوْرَدَهُ أَبُو دَاوُدَ مَرْفُوعاً [3]‏ .‏