From the Catholic Answers forum:
I was told that Gen 3:15 was always translated as "she shall crush thy head, and thou shalt lie in wait for her heel."(D-R translation) until Luther changed it to "he" and "his". Is this true? What is the word in the original language, is it gender neutral? Why would Luther change it, didn't he have a great devotion to Mary?
And It will crush your head, and you will crush Its heel.
How amazing, how damnable, that through the agency of foolish exegetes Satan has managed to apply this passage, which in fullest measure abounds in the comfort of the Son of God, to the Virgin Mary! For in all the Latin Bibles the pronoun appears in the feminine gender: “And she will crush.” Even Lyra, who was not unfamiliar with the Hebrew language, is carried away by this error as by a swollen and raging torrent. So he is brought to the wicked position, despite the text, that he understands this passage of the Blessed Virgin, through whom, by the mediation of her Son, the power of Satan has been broken. He applies to her the statement in Canticles (Song of Sol. 6:4): “Thou art terrible as an army set in array.” Although he offers this opinion as one which he has received from others, his great sin consists in not refuting it. All the recent interpreters have followed along and misused this most sacred statement for the purpose of idolatry, without anyone objecting to it or preventing it.
This happened through either ignorance of negligence on the part of the rulers in the church. Because they offered no resistance to idolatry, sound teaching gradually disappeared. Now that we have restored it by the grace of God, these shameful and gluttonous beasts show clearly that they do not care about the worship of God but only about their ecclesiastical revenues. Because idolatry seems to afford protection to these revenues, they are provoked when men are taught the truth. In their blindness they do not see that those who accept the teaching of the Gospel lose nothing except their sins and eternal death, but gain freedom from all idolatry and from the rule of Satan.
Therefore let us thank God that now we have also this passage unimpaired and restored. We do not want to take away from Mary any honor which is her due; but we want to remove the idolatry contained in the statement that by giving birth to Christ, Mary has destroyed all the power of Satan. If this is a true statement, does not the same honor belong to all the other women who preceded Mary in the same line? In fact, a portion of this glory will belong also to their husbands and to all the ancestors of Mary. For if she had not had these, she herself would not have existed either, since she was born in wedlock according to the usual order of nature. If, therefore, she has destroyed Satan by giving birth to Christ, her ancestors must be given a position of honor on the same level.
But Scripture teaches us otherwise and declares (Rom. 4:25): “Christ died for our sins and rose again for our justification”; likewise (John 1:29): “Behold the Lamb of God, which bears the sins of the world.” Therefore let the Blessed Virgin keep her place of honor. Among all the women of the world she has this privilege from God, that as a virgin she gave birth to the Son of God. But this must not be permitted to deprive her Son of the glory of our redemption and deliverance.
Then we must be careful to preserve the real meaning of the Holy Scriptures and their truly wonderful light. When we are given instruction in this passage concerning the enmity between the serpent and the woman—such an enmity that the Seed of the woman will crush the serpent with all his powers—this is a revelation of the depths of God’s goodness. Satan understood this threat well; therefore he has continued to rage against human nature with such great hatred. Adam and Eve were encouraged by this promise. Wholeheartedly they grasped the hope of their restoration; and, full of faith, they saw that God cared about their salvation, since He clearly declares that the male Seed of the woman would prostrate this enemy. The order of words in this sentence is very forceful.
He says “her Seed.” It is as if He were saying: “Through the woman you, Satan, set upon and seduced the man, so that through sin you might be their head and master. But I, in turn, shall lie in wait for you by means of the same instrument. I shall snatch away the woman, and from her I shall produce a Seed, and that Seed will crush your head. You have corrupted the flesh through sin and have made it subject to death, but from that very flesh I shall bring forth a Man who will crush and prostrate you and all your powers.”
Thus this promise and this threat are very clear, and yet they are also very indefinite. They leave the devil in such a state that he suspects all mothers of giving birth to this Seed, although only one woman was to be the mother of this blessed Seed. Thus because God is threatening in general when He says “her Seed,” He is mocking Satan and making him afraid of all women.
In the same way the faith of all people was strengthened; from the hour in which the promise was made they waited for the Seed and derived comfort from It against Satan. When Eve had given birth to her first-born son, she hoped that she already had that Crusher. Although she was deceived in this hope, she saw that eventually this Seed would be born from among her descendants, whenever it might be that He would be born. Also so far as human beings were concerned, therefore, this promise was very clear and at the same time very obscure.
Isaiah (7:14) threw some light on this when he said that a virgin would give birth, for at that time it was already sure that this Seed would not be born as the result of the union of a man and a woman. But he adds certain other statements which, so to speak, he wraps around his prophecy. So it was that this very clear promise remained dark until Mary had given birth; the angels were witnesses of this birth, and after the angels the shepherds and the Magi, until this birth was revealed to the entire world through the apostles.
Luther, M. (1999, c1958). Vol. 1: Luther's works, vol. 1 : Lectures on Genesis: Chapters 1-5 (J. J. Pelikan, H. C. Oswald & H. T. Lehmann, Ed.). Luther's Works (1:191). Saint Louis: Concordia Publishing House.
But I return to the text. This very clear promise is at the same time also very obscure, because God speaks in general of “the Seed of the woman.” Thus at the same time He makes all women suspect to Satan and worries him with endless concern and care. It is, therefore, an amazing instance of synecdoche. “the woman’s Seed,” He says. This means all individuals in general; and yet He is speaking of only one individual, of the Seed of Mary, who is a mother without union with a male. Thus the first little expression, “I shall put enmity between you and the woman,” seems to denote all women in general. God wanted to make all women suspect to Satan; on the other hand, He wanted to leave the godly with a very certain hope, so that they might expect this salvation from all who gave birth, until the real one came. In the same way this “her Seed” is spoken most individually, if I may use this expression, concerning the Seed which was born only to Mary of the tribe of Judah, who was espoused to Joseph.
Luther, M. (1999, c1958). Vol. 1: Luther's works, vol. 1 : Lectures on Genesis: Chapters 1-5 (J. J. Pelikan, H. C. Oswald & H. T. Lehmann, Ed.). Luther's Works (1:195). Saint Louis: Concordia Publishing House.