Or HaChaim on Genesis 32:27/אור החיים על בראשית ל״ב:כ״ז

1 לא אשלחך, "I will not let you depart, etc." When the angel said to Jacob that he had struggled with a celestial being and had prevailed, he meant that he now could not depart without Jacob's permission. When Jacob said: "unless you bless me," he meant that he would assure him that the injury he caused to Jacob's hip-joint would not be permanent. It is also possible that the mere fact that Jacob now realised he had wrestled with an angel prompted him to ask for a blessing from that angel.