Therefore the children of Israel eat not of the sinew which shrank, which is upon the hollow of the thigh, unto this day: because he touched the hollow of Jacob's thigh in the sinew that shrank.

Jamieson-Fausset-Brown Bible Commentary

32. the sinew which shrank-the nerve that fastens the thigh bone in its socket. The practice of the Jews in abstaining from eating this in the flesh of animals, is not founded on the law of Moses, but is merely a traditional usage. The sinew is carefully extracted; and where there are no persons skilled enough for that operation, they do not make use of the hind legs at all.

Matthew Henry's Concise Commentary

32:24-32 A great while before day, Jacob being alone, more fully spread his fears before God in prayer. While thus employed, One in the likeness of a man wrestled with him. When the spirit helpeth our infirmities, and our earnest and vast desires can scarcely find words to utter them, and we still mean more than we can express, then prayer is indeed wrestling with God. However tried or discouraged, we shall prevail; and prevailing with Him in prayer, we shall prevail against all enemies that strive with us. Nothing requires more vigour and unceasing exertion than wrestling. It is an emblem of the true spirit of faith and prayer. Jacob kept his ground; though the struggle continued long, this did not shake his faith, nor silence his prayer. He will have a blessing, and had rather have all his bone put out of joint than go away without one. Those who would have the blessing of Christ, must resolve to take no denial. The fervent prayer is the effectual prayer. The Angel puts a lasting mark of honour upon him, by changing his name. Jacob signifies a supplanter. From henceforth he shall be celebrated, not for craft and artful management, but for true valour. Thou shalt be called Israel, a prince with God, a name greater than those of the great men of the earth. He is a prince indeed that is a prince with God; those are truly honourable that are mighty in prayer. Having power with God, he shall have power with men too; he shall prevail, and gain Esau's favour. Jacob gives a new name to the place. He calls it Peniel, the face of God, because there he had seen the appearance of God, and obtained the favour of God. It becomes those whom God honours, to admire his grace towards them. The Angel who wrestled with Jacob was the second Person in the sacred Trinity, who was afterwards God manifest in the flesh, and who, dwelling in human nature, is called Immanuel, Ho 12:4,5. Jacob halted on his thigh. It might serve to keep him from being lifted up with the abundance of the revelations. The sun rose on Jacob: it is sun-rise with that soul, which has had communion with God.