What is the ruling on swearing by divorce while angry, after the family misunderstood a conversation, and the ruling on swearing not to accompany one's sister for the Shariah-sanctioned viewing (Ru'yah Shar'iyyah) and then accompanying her?

If you swore by one of Allah's names or attributes to abandon or perform something, and then broke your oath, you owe an expiation for breaking an oath (kaffarat yameen). If you broke both of the aforementioned oaths, you owe an expiation for each one. If you broke only one of them, then you owe expiation for the one you broke. The expiation is to feed ten poor persons from the average of what you feed your own families, or to clothe them, or to free a slave. And whoever cannot find means, then he must fast for three days.