Answer
(Fatwa: 920/920=M/1430)
If you took oath of the Quran to do a thing, but you failed to do it, so you will have to pay the kaffarah (expiation). The kaffarah of an oath is to feed ten poor persons for two times or to give 1.575 kg wheat or its price (equal to Sadaqatul Fitr) to ten poor, or to give cloth to ten poor which can cover most of their body. If someone is unable to feed or give cloth, he can keep sawm (fast) for three consecutive days:
وکفارتہ تحریر رقبۃ أو إطعام عشرۃ مساکین کما مر في الظھار أو کسوتھم بما یستر عامۃ البدن فلم یجز السراویل لأن لابسہ یسمی عریانا عرفا الخ (الدر المختار مع الشامي) فإن لم یقدر علی أحد الأشیاء الثلاثۃ صام ثلاثۃ أیام متتابعات (شرح البدایۃ)
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband