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.
Allah will not impose blame upon you for what is meaningless1 in your oaths, but He will impose blame upon you for [breaking] what you intended of oaths. So its expiation2 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.3 Thus does Allah make clear to you His verses [i.e., revealed law] that you may be grateful.