Ata narrated: I and Ubaid bin Umair went to Aisha (may Allah be pleased with her) while she was observing i'tikaf at the place of Shaheer. I asked her about Allah's statement: "Allah will not call you to account for your unintentional oaths" (__QUR_N__: Al-Baqarah: 225). She replied: "These are (the oaths which people utter habitually, such as) 'No, by Allah!' or 'Yes, by Allah!'"
Hadith Referenceمسند الإمام الشافعي / كتاب القضاء والأحكام والدعاوى والبينات واليمين ومع الشاهد والأيمان والشهادات / 1723
Hadith Takhrijاخرجه ابو داود الايمان والنذور، باب لغو اليمين (3254) وصححه ابن حبان۔