I will put enmity, &c. The whole race of serpents are, of all creatures, the most disagreeable and terrible to mankind, and especially to women: but the devil, who seduced the woman, and his angels, are here meant, who are hated and dreaded by all men, even by those that serve them, but more especially by good men. And between thy seed All carnal and wicked men, who, in reference to this text, are called the children and seed of Satan; and her seed That is, her offspring, first and principally CHRIST, who, with respect to this promise, is termed, by way of eminence, her seed, (see Galatians 3:16; Galatians 3:19,) whose alone work it is to bruise the serpent's head, to destroy the policy and power of the devil. But also, secondly, all the members of Christ, all believers and holy men, are here intended, who are the seed of Christ and the implacable enemies of the devil and his works, and who overcome him by Christ's merit and power.
It shall bruise thy head The principal instrument of the serpent's fury and mischief, and of his defence; and also the chief seat of his life, which, therefore, men chiefly strike at, and which, being upon the ground, a man may conveniently tread upon and crush to pieces. Applied to Satan, this denotes his subtlety and power, producing death, which Christ, the Seed of the woman, destroys by taking away its sting, which is sin.
Thou shalt bruise his heel The part which is most within the serpent's reach, and on which, being bruised by it, the serpent is provoked to fix its venomous teeth, but a part remote from the head and heart, and therefore wounds there, though painful, are yet not deadly nor dangerous, if they be observed in time. Understood of Christ, the seed of the woman, his heel means, first, his humanity, whereby he trod upon the earth, and which the devil, through the instrumentality of wicked men, bruised and killed; and, secondly, his people, his members, whom Satan, in divers ways, bruises, vexes, and afflicts while they are on earth, but cannot reach either Christ their head in heaven, or themselves when they shall be advanced thither. In this verse, therefore, notice is given of a perpetual quarrel commenced between the kingdom of God and the kingdom of the devil among men: war is proclaimed between the seed of the woman and the seed of the serpent, Revelation 12:7. It is the fruit of this enmity, 1st, That there is a continual conflict between God's people and him. Heaven and hell can never be reconciled, no more can Satan and a sanctified soul. 2d, That there is likewise a continual struggle between the wicked and the good. And all the malice of persecutors against the people of God is the fruit of this enmity, which will continue while there is a godly man on this side heaven, and a wicked man on this side hell. But, 3d, A gracious promise also is here made of Christ, as the deliverer of fallen man from the power of Satan. By faith in this promise, our first parents, and the patriarchs before the flood, were justified and saved; and to this promise, and the benefit of it, instantly serving God day and night, they hoped to come.