Sahih al-Bukhari — Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) — Hadith No: 4613
Translation
Narrated `Aisha:This Verse: "Allah will not punish you for what is unintentional in your oaths." (5.89) was revealed about a man's statement (during his talk), "No, by Allah," and "Yes, by Allah