In this chapter, Jacob begins his journey to Canaan and encounters God again.
The first thing Jacob sees after parting from Laban is angels, who "met him". It does not state what they said or did, but remember what I said before about the role of angels in the bible: they are messengers and delegated authorities of the one who sends them. We don't know how they interacted with Jacob, but they serve as a portent for God.
Next, Jacob finally has to return to his land and make peace with his brother. This is a full 20 years after they had last met, and both are now surely much older than they were before. Nevertheless, Jacob still fears the grudge of his brother, and his servile tone shows all of the deference in the world for the man who he fears will try to kill him. Yet Esau's response is all the more cause for alarm, because Esau is coming with 400 armed men, certainly a large enough group to murder Jacob and everyone with him. Remember that Laban was able to catch him because of all of the flocks and herds and children slowing him down, and the same is true of Esau: Jacob is in absolutely no military position to resist him.
Note that Jacob dividing his camp into two groups is both tactically smart, but it's also a pun on Mahanaim. Before the "mahanaim" was his camp and the angels', but now they are both his.
Jacob prays to God for protection, again showing the change in character since when he first departed Canaan. Jacob prepares some gifts for Esau and then has his second profound encounter with God.
The first encounter, fittingly enough, was when Jacob was fleeing Canaan and fleeing Esau. He had nothing but his staff. Now, in his second noteworthy encounter, Jacob is returning to Canaan and going to meet the same brother he had fled from 20 years before. He is now extremely wealthy and has a large family, desirable things for any man of the time. More importantly, he had been subjected to the treachery of Laban over those 20 years and has slowly developed a willingness to depend on God for protection rather than rely on his own means, through deception and manipulation. There is no sign that he is now considering deceiving his brother, even though his departure from Laban still showed that Jacob has some lingering reliance on deception.
For the contents of the encounter, there are a couple things I'd like to note. First, remember that Jacob means "grasping at the heel", which in my mind is an allusion to wrestling. Thus one could say that his wrestling against God is a reference to his name, which is also emblematic of his character throughout this whole story. God says that he wrestled with men as well, and this is also an allusion to his name.
Second, I really think this episode speaks a lot to Jacob's character in general. When has there been a time in this whole story that Jacob is not struggling with somebody, whether it's Esau or Isaac or Laban?
Third, I find it peculiar how the story just says that "a man wrestled with him". It doesn't really say where the man came from or how they were matched. It seems that Jacob just wandered off until he was alone, and then this man came and grappled with him. Well, "wandered off" is perhaps not correct, because we know that Jacob was sending his family and his belongings across the river, so presumably this included all of his servants and possessions. It's unusual that he would do this in the middle of the night, and that too is unexplained. Additionally, Jacob seems to discern that this man is God, yet we are never exactly told how he knew. Jacob's insistence that the man bless him only seems to make sense if Jacob knew it was God, but even so, this whole episode seems surreal. Where were all of Jacob's servants and wives and children? It is unusual that they would all be separated from him on the eve of such an important and threatening encounter with Esau. This set of events almost seems more consistent with a dream or a vision than real events, though perhaps in the end it is not very important one way or the other.
Fourth, when the man asks, Jacob tells him his real name. The last time Jacob is recorded as telling someone his name, it was when his father Isaac asked and his answer was Esau. This, I believe, is the conclusion of Jacob's redemption arc, as he is finally given the opportunity to right his previous wrong, and that on the eve of meeting Esau again.
Fifth, God renames Jacob to Israel. Going forward, these two names are used interchangeably in the Bible, so do not be confused when Israel (the nation) is sometimes called Jacob, or Jacob is called Israel. They are basically the same thing, as far as the biblical authors are concerned. The last person to be renamed in the bible was Abraham (well, and Sarah too.... well, Esau was also named to Edom... moving on). In Abraham's case, his name was changed from Abram (exalted father) to Abraham (father of nations/multitudes), showing a subtle but important transformation as he is given the promise that he will be a father of nations. Jacob's case is similar. He is renamed from Jacob, "grasping at the heel/deceiver" to Israel, "wrestles/contends with God". This is yet another significant element of Jacob's redemption which does not destroy his character (he is still as aggressive as ever), but it redeems his character, by stripping out the fleshly elements of deception and manipulation and leaving the fiery core that seeks to contend with the whole world.
Lastly, it says that God blessed Jacob. Jacob walked with a limp after that event. Some people speculate that he was injured for the rest of his life, although I don't believe the text actually makes any reference to Jacob's limp after this chapter. In some respects, one could downplay Jacob's limp, and yet it says the Israelites never ate the sinew attached to the hip because that's where Jacob was touched.
Other people have written at great length about Jacob's limp, and preachers have preached on it multitudes of times, so I feel like I should say something more, but I honestly don't know what I really want to say: that wrestling will always leave you bruised a bit? Maybe, but that doesn't feel very insightful. That God injures people? It sounds kinda funny to say, but again I don't really perceive much significance there.
I feel like I've done a lot of "wrestling with God", and yet I can think of few parallels in my life to the injury that Jacob sustains. I guess I'll just leave it at that. If my readers desire a more detailed interpretation, they can search through other sources and judge the quality of those interpretations. For my part, while I recognize that many have extrapolated much from this passage, I don't know how much of what is said can be justified by the text. I don't see anything in the story that shows some particular significance of the hip, or of Jacob's injury in any larger context. It just seems to happen, and then that's it, the end of the encounter. Everything else that I have mentioned, from Jacob's struggles with deception and his renaming to Israel, have significant connections to other chapters in Genesis and indeed the rest of the story of Israel at large.
In conclusion, Jacob contended with God for a blessing, and a blessing he received. As well as a new name and identity, purged of the unfortunate connotations and patterns of his youth, even since birth. While this concludes Jacob's redemption arc (in my opinion), it does not conclude his story, which will pick up in the next chapter when Jacob finally meets Esau face to face.
As a minor addendum, note that the people in the bible thought that someone would die if they saw God face to face. That's one of the reasons why a lot of people in the bible freak out when they see God's face.