Interesting things in Obadiah:
7 All the men of thy confederacy have brought thee even to the border: the men that were at peace with thee have deceived thee, and prevailed against thee; they that eat thy bread have laid a wound under thee: there is none understanding in him.
I think this might mean (confederacy.. is there a group of Arab nations, some type of formal name? I think there is, I just can't think of it right now) but this group that supposedly stands together may sell them out)
10 For thy violence against thy brother Jacob shame shall cover thee, and thou shalt be cut off for ever.
I think this goes back to when Esau wanted food and traded his birthright for food. Later he was resentful over this, even though it was his own fault. Responsibility for his actions. Revenge for Jacob having the birthright that Esau trade away.