The kingdom of Edom was established by Jacob's twin Esau, hence thy brother Israel. Moses (representing Israel) sending messengers to Edom harks back to the much earlier episode of Jacob himself sending messengers to his brother to make amends for stealing his birthright. The original response, Esau ran to meet him, and embraced him was one of love and forgiveness¹ but in this case it is the opposite. Esau's descendent, the king of Edom does not acknowledge brotherhood, and refuses the Israelites permission to cross his land. What are we to make of that?

The wrongs we commit, although perhaps forgiven by those we have wronged sometimes stay internalised to haunt us, and the associated shame and regret may still surface after years. Whereas guilt can be dealt with externally, punishment meted, forgiveness offered, and action taken to amend the wrongdoing, shame and regret are internalised.² Although Esau wholeheartedly forgave his brother, Jacob was not fully able to forgive himself, and the shame of his behaviour lived on within him, propagating to his descendants, metaphorically speaking. I can imagine that it was the way in which Israel makes the request of Edom that resulted in the refusal. They grovelled, they lowered themselves, they came with all their shame and feelings of regret. Had Jacob forgiven himself, as his brother forgave him, the absence of shame may have made the request a more egalitarian one, brother to brother as it were, not supplicant to superior. It is not our actions that cause future damage to our relationships, it is the feelings of personal wrongness the action evoked, and that we carry with us, like a useless burden.

¹ Genesis 33:4
² The difference can be described thus. Guilt is a feeling you get when you did something wrong, or perceived you did something wrong. Shame is a feeling that your whole self is wrong, and it may not be related to a specific behaviour or event. [ref]
^music Shame by The Avett Brothers, from the album Emotionalism 2007