Charles Ellicott Commentary Genesis 32:29

"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)

Wherefore ... — In much the same manner the angel refuses to tell Manoah his name (Judges 13:18). Probably, however, in the blessing which followed there was a clear proof that Jacob’s opponent was a Divine personage.