Al-Ma'idah 5:89 لا يواخذكم الله باللغو في ايمانكم ولاكن يواخذكم بما عقدتم الايمان فكفارته اطعام عشرة مساكين من اوسط ما تطعمون اهليكم او كسوتهم او تحرير رقبة فمن لم يجد فصيام ثلاثة ايام ذالك كفارة ايمانكم اذا حلفتم واحفظوا ايمانكم كذالك يبين الله لكم اياته لعلكم تشكرون ٨٩

God does not take you [to task] for what is thoughtless in your oaths, only for your binding oaths: the atonement for breaking an oath is to feed ten poor people with food equivalent to what you would normally give your own families, or to clothe them, or to set free a slave- if a person cannot find the means, he should fast for three days. This is the atonement for breaking your oaths- keep your oaths. In this way God makes clear His revelations to you, so that you may be thankful.