The Cow - 2:225
Allah does not hold you responsible for your unintentional oaths, but He holds you responsible for the true intention in your hearts. Allah is Forgiving, Compassionate.
Allah holds responsible those who swear deliberately:
The Table Spread/5:89
Allah does not hold you responsible for the oaths you take at random. But He holds you responsible for what you swear knowingly. If you break your oath, the punishment is to feed or clothe ten poor out of what you usually feed your family, or to release a slave. Whoever cannot find it should fast for three days. This is the punishment for your oaths that you knowingly took. Keep your oaths. This is how Allah explains His verses so that you may respond well.