There wrestled a man with him [1] Although this vision was particularly useful to Jacob himself, to teach him beforehand that many conflicts awaited him, and that he might certainly conclude that he should be the conqueror in them all; there is yet not the least doubt that the Lord exhibited, in his person, a specimen of the temptations -- common to all his people -- which await them, and must be constantly submitted to, in this transitory life. Wherefore it is right to keep in view this designs of the vision, which is to represent all the servants of God in this world as wrestlers; because the Lord exercises them with various kinds of conflicts. Moreover, it is not said that Satan, or any mortal man, wrestled with Jacob, but God himself: to teach us that our faith is tried by him; and whenever we are tempted, our business is truly with him, not only because we fight under his auspices, but because he, as an antagonist, descends into the arena to try our strength. This, though at first sight it seems absurd, experience and reason teaches us to be true. For as all prosperity flows from his goodness, so adversity is either the rod with which he corrects our sins, or the test of our faith and patience. And since there is no kind of temptations by which God does not try his faithful people, the similitude is very suitable, which represents him as coming, hand to hand, to combat with them. Therefore, what was once exhibited under a visible form to our father Jacob, is daily fulfilled in the individual members of the Church; namely, that, in their temptations, it is necessary for them to wrestle with God. He is said, indeed, to tempt us in a different manner from Satan; but because he alone is the Author of our crosses and afflictions, and he alone creates light and darkness, (as is declared in Isaiah,) he is said to tempt us when he makes a trial of our faith. But the question now occurs, Who is able to stand against an Antagonist, at whose breath alone all flesh perishes and vanishes away, at whose look the mountains melt, at whose word or beck the whole world is shaken to pieces, and therefore to attempt the least contest with him would be insane temerity? But it is easy to untie the knot. For we do not fight against him, except by his own power, and with his own weapons; for he, having challenged us to this contest, at the same time furnishes us with means of resistance, so that he both fights against us and for us. In short, such is his apportioning of it is conflict, that, while he assails us with one hand, he defends us with the other; yea, inasmuch as he supplies us with more strength to resist than he employs in opposing us, we may truly and properly say, that he fights against us with his left hand, and for us with his right hand. For while he lightly opposes us, he supplies invincible strength whereby we overcome. It is true he remains at perfect unity with himself: but the double method in which he deals with us cannot be otherwise expressed, than that in striking us with a human rod, he does not put forth his full strength in the temptation; but that in granting the victory to our faith, he becomes in us stronger than the power by which he opposes us. And although these forms of expression are harsh, yet their harshness will be easily mitigated in practice. For if temptations are contests, (and we know that they are not accidental, but are divinely appointed for us,) it follows hence, that God acts in the character of an antagonist, and on this the rest depends; namely, that in the temptation itself he appears to be weak against us, that he may conquer in us. Some restrict this to one kind of temptation only, where God openly and avowedly manifests himself as our adversary, as if armed for our destruction. And truly, I confess, that this differs from common conflicts, and requires, beyond all others, a rare, and even heroic strength. Yet I include willingly every kind of conflict in which God exercises the faithful: since in all they have God for an antagonist, although he may not openly proclaim himself hostile unto them. That Moses here calls him a man whom a little after he declares to have been God, is a sufficiently usual form of speech. For since God appeared under the form of a man, the name is thence assumed; just as, because of the visible symbol, the Spirit is called a dove; and, in turn, the name of the Spirit is transferred to the dove. That this disclosure was not sooner made to the holy man, I understand to be for this reason, because God had resolved to call him, as a soldier, robust and skillful in war, to more severe contests. For as raw recruits are spared, and young oxen are not immediately yoked to the plough; so the Lord more gently exercises his own people, until, having gathered strength, they become more inured to toil. Jacob, therefore, having been accustomed to bear sufferings, is now led forth to real war. Perhaps also, the Lord had reference to the conflict which was then approaching. But I think Jacob was admonished, at his very entrance on the promised land, that he was not there to expect a tranquil life for himself. For his return to his own country might seem to be a kind of release; and thus Jacob, like a soldier who had kept his term of service, would have given himself up to repose. Wherefore it was highly necessary for him to be taught what his future conditions should be. We, also, are to learn from him, that we must fight during the whole course of our life; lest any one, promising himself rest, should wilfully deceive himself. And this admonition is very needful for us; for we see how prone we are to sloth. Whence it arises, that we shall not only be thinking of a truce in perpetual war; but also of peace in the heat of the conflict, unless the Lord rouse us.

Footnotes

1 - y'vq, yebek, from 'vq, dust, because in wrestling the dust is raised. -- Gesenius.

And there wrestled a man with him - This was doubtless the Lord Jesus Christ, who, among the patriarchs, assumed that human form, which in the fullness of time he really took of a woman, and in which he dwelt thirty-three years among men. He is here styled an angel, because he was μεγαλης βουλης Αγγελος, (see the Septuagint, Isaiah 9:7), the Messenger of the great counsel or design to redeem fallen man from death, and bring him to eternal glory; see Genesis 16:7.
But it may be asked, Had he here a real human body, or only its form? The latter, doubtless. How then could he wrestle with Jacob? It need not be supposed that this angel must have assumed a human body, or something analogous to it, in order to render himself tangible by Jacob; for as the soul operates on the body by the order of God, so could an angel operate on the body of Jacob during a whole night, and produce in his imagination, by the effect of his power, every requisite idea of corporeity, and in his nerves every sensation of substance, and yet no substantiality be in the case.
If angels, in appearing to men, borrow human bodies, as is thought, how can it be supposed that with such gross substances they can disappear in a moment? Certainly they do not take these bodies into the invisible world with them, and the established laws of matter and motion require a gradual disappearing, however swiftly it may be effected. But this is not allowed to be the case, and yet they are reported to vanish instantaneously. Then they must render themselves invisible by a cloud, and this must be of a very dense nature in order to hide a human body. But this very expedient would make their departure still more evident, as the cloud must be more dense and apparent than the body in order to hide it. This does not remove the difficulty. But if they assume a quantity of air or vapor so condensed as to become visible, and modified into the appearance of a human body, they can in a moment dilate and rarefy it, and so disappear; for when the vehicle is rarefied beyond the power of natural vision, as their own substance is invisible they can instantly vanish.
From Hosea 12:4, we may learn that the wrestling of Jacob, mentioned in this place, was not merely a corporeal exercise, but also a spiritual one; He wept and made supplication unto him. See Clarke on Hosea 12:4 (note).

And Jacob was left alone; and there wrestled a (h) man with him until the breaking of the day.
(h) That is, God in the form of a man.

And Jacob was left alone,.... On the other side of Jabbok, his family and cattle having passed over it; and this solitude he chose, in order to spend some time in prayer to God for the safety of him and his:
and there wrestled a man with him; not a phantasm or spectre, as Josephus (e) calls him; nor was this a mere visionary representation of a man, to the imagination of Jacob; or done in the vision of prophecy, as Maimonides (f); but it was something real, corporeal, and visible: the Targum of Jonathan says, it was an angel in the likeness of a man, and calls him Michael, which is not amiss, since he is expressly called an angel, Hosea 12:4; and if Michael the uncreated angel is meant, it is most true; for not a created angel is designed, but a divine Person, as appears from Jacob's desiring to be blessed by him; and besides, being expressly called God, Genesis 32:28; and was, no doubt, the Son of God in an human form; who frequently appeared in it as a token and pledge of his future incarnation: and "this wrestling" was real and corporeal on the part of both; the man took hold of Jacob, and he took hold of the man, and they strove and struggled together for victory as wrestlers do; and on Jacob's part it was also mental and spiritual, and signified his fervent and importunate striving with God in prayer; or at least it was attended with earnest and importunate supplications; see Hosea 12:4; and this continued
until the breaking of the day: how long this conflict lasted is not certain, perhaps not long; since after Jacob rose in the night he had a great deal of business to do, and did it before this affair happened; as sending his wives, children, servants, and cattle over the brook: however, this may denote, that in the present state or night of darkness, wrestling in prayer with God must be continued until the perfect state commences, when the everlasting day of glory will break.
(e) Antiqu. l. 1. c. 20. sect. 2. (f) Morch Nevochim, par. 2. c. 42. p. 310.

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, Hosea 12:4, Hosea 12:5. 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.

There wrestled a man with him--This mysterious person is called an angel (Hosea 12:4) and God (Genesis 32:28, Genesis 32:30; Hosea 12:5); and the opinion that is most supported is that he was "the angel of the covenant," who, in a visible form, appeared to animate the mind and sympathize with the distress of his pious servant. It has been a subject of much discussion whether the incident described was an actual conflict or a visionary scene. Many think that as the narrative makes no mention in express terms either of sleep, or dream, or vision, it was a real transaction; while others, considering the bodily exhaustion of Jacob, his great mental anxiety, the kind of aid he supplicated, as well as the analogy of former manifestations with which he was favored--such as the ladder--have concluded that it was a vision [CALVIN, HESSENBERG, HENGSTENBERG]. The moral design of it was to revive the sinking spirit of the patriarch and to arm him with confidence in God, while anticipating the dreaded scenes of the morrow. To us it is highly instructive; showing that, to encourage us valiantly to meet the trials to which we are subjected, God allows us to ascribe to the efficacy of our faith and prayers, the victories which His grace alone enables us to make.

Very early in the morning, a great while before day. Jacob had helped his wives and children over the river, and he desired to be private, and was left alone, that he might again spread his cares and fears before God in prayer. While Jacob was earnest in prayer, stirring up himself to take hold on God, an angel takes hold on him. Some think this was a created angel, one of those that always behold the face of our Father. Rather it was the angel of the covenant, who often appeared in a human shape, before he assumed the human nature. We are told by the prophet, Hosea 12:4, how Jacob wrestled, he wept and made supplication; prayers and tears were his weapons. It was not only a corporal, but a spiritual wrestling by vigorous faith and holy desire.