Or HaChaim on Genesis 32:12/אור החיים על בראשית ל״ב:י״ב

1 הצילני נא, "Save me please!" He used the word נא, a combined form of "please" and "now." He pleaded with G'd not to allow Esau to cause him any losses instead of letting him recoup his losses later on.

2מיד אחי, מיד עשו, from my brother's hand, from Esau's hand. Rashi understands the word אחי as a plea that Esau should not treat him like a brother but rather as befitted the wicked Esau. According to this explanation Jacob should only have said מיד אחי עשו, and we would have understood the Torah's meaning from the otherwise superfluous "my brother," seeing that Esau was his only brother.

3I believe therefore that the correct meaning is that Jacob prayed and addressed himself to the fact that there were two facets to Esau's character. On the one hand Esau was a son of Isaac and Isaac's merits would assist him. On the other hand, he was a person in his own right, a very powerful person at that; it would require great strength to be saved from attack by such a person. Jacob therefore prayed to G'd that Isaac's merit should not now assist him; this is what he meant by "save me please from the hands of my brother," i.e. although he is my brother. Concerning Esau's being a powerful adversary in his own right, Jacob prayed "please save me from Esau!"

4Jacob also had in mind that if Esau were to use the fact that he was his brother as a trick to attack him after feigning brotherliness, G'd should save him from such machinations. He also needed G'd's help, however, if Esau proclaimed his hostility openly.

5Jacob also drew G'd's attention to the enormity of Esau's crime if he were to try and murder his own brother, מיד אחי; surely the mere thought of committing such a heinous crime should provide sufficient excuse for G'd to humble Esau; on the other hand, Esau's wickedness (without considering the fact that in this case he set out to murder a brother) was sufficient to warrant G'd's intervention on behalf of Jacob.