Surah Al-Ma'idah, ayah 89

لَا يُؤَاخِذُكُمُ ٱللَّهُ بِٱللَّغۡوِ فِيٓ أَيۡمَٰنِكُمۡ وَلَٰكِن يُؤَاخِذُكُم بِمَا عَقَّدتُّمُ ٱلۡأَيۡمَٰنَۖ فَكَفَّٰرَتُهُۥٓ إِطۡعَامُ عَشَرَةِ مَسَٰكِينَ مِنۡ أَوۡسَطِ مَا تُطۡعِمُونَ أَهۡلِيكُمۡ أَوۡ كِسۡوَتُهُمۡ أَوۡ تَحۡرِيرُ رَقَبَةٖۖ فَمَن لَّمۡ يَجِدۡ فَصِيَامُ ثَلَٰثَةِ أَيَّامٖۚ ذَٰلِكَ كَفَّٰرَةُ أَيۡمَٰنِكُمۡ إِذَا حَلَفۡتُمۡۚ وَٱحۡفَظُوٓاْ أَيۡمَٰنَكُمۡۚ كَذَٰلِكَ يُبَيِّنُ ٱللَّهُ لَكُمۡ ءَايَٰتِهِۦ لَعَلَّكُمۡ تَشۡكُرُونَ ٨٩

Lā yu'ākhidhukumullāhu bil-laghwi fī aymānikum walākin yu'ākhidhukum bimā 'aqqattumul-aymāna fakaffāratuhū it'āmu 'asharati masākīna min awsati mā tut'imūna ahlīkum aw kiswatuhum aw tahrīru raqabatin famal lam yajid fasiyāmu thalāthati ayyāmin dhālika kaffāratu aymānikum idhā halaftum wahfazū aymānakum kadhālika yubayyinullāhu lakum āyātihī la'allakum tashkurūn

Allāh will not impose blame upon you for what is meaningless²⁷⁹ in your oaths, but He will impose blame upon you for [breaking] what you intended of oaths. So its expiation²⁸⁰ is the feeding of ten needy people from the average of that which you feed your [own] families or clothing them or the freeing of a slave. But whoever cannot find [or afford it] - then a fast of three days [is required]. That is the expiation for oaths when you have sworn. But guard your oaths.²⁸¹ Thus does Allāh make clear to you His verses [i.e., revealed law] that you may be grateful.