And Jacob was left alone; and there wrestled a man with him until the breaking of the day. (Genesis 32:24, ASV)
Jacob is on his way home to meet with his brother when he encounters a "man" and wrestles with him through the night. The prophet Hosea identifies this "man" as a "messenger" (Hosea 12:4). Verses 25 through 27 tell us that Jacob was winning the struggle and the man causes Jacob to go lame and then asks Jacob for his name.
And he said, Thy name shall be called no more Jacob, but Israel: for thou hast striven with God and with men, and hast prevailed. (Genesis 32:28, ASV)
The man gives Jacob a new name, Israel, but this is not the only time this renaming is recorded. In Genesis 35:10 we read that it was Elohim who gives him the name Israel. Then in the next verse Elohim identifies himself as El of Shaddai. In chapter 32 we have a "man" giving Jacob the name Israel, but in chapter 35 it is El of Shaddai. There are two ways to interpret this. The first is that a man first gives Jacob his new name and El of Shaddai confirms what the man has done or second, El of Shaddai is the man who gives him the new name in the first place. I prefer the second interpretation, but let's continue on with the narrative.
And Jacob asked him, and said, Tell me, I pray thee, thy name. And he said, Wherefore is it that thou dost ask after my name? And he blessed him there. (Genesis 32:29, ASV)
Jacob then asks the man for his name, but he does not give it to him, instead he blesses him.
And Jacob called the name of the place Peniel: for, said he, I have seen God face to face, and my life is preserved. (Genesis 32:30, ASV)
According to this verse Jacob "saw the face of Elohim." The only logical conclusion is that Jacob believed that the man he wrestled was Elohim, and appears to be El of Shaddai.