Romans 7:2

2.For a woman subject to a man, etc. He brings a similitude, by which he proves, that we are so loosed from the law, that it does not any longer, properly and by its own right, retain over us any authority: and though he could have proved this by other reasons, yet as the example of marriage was very suitable to illustrate the subject, he introduced this comparison instead of evidence to prove his point. But that no one may be puzzled, because the different parts of the comparison do not altogether correspond, we are to be reminded, that the Apostle designedly intended, by a little change, to avoid the invidiousness of a stronger expression. He might have said, in order to make the comparison complete, “A woman after the death of her husband is loosed from the bond of marriage: the law, which is in the place of a husband to us, is to us dead; then we are freed from its power.” But that he might not offend the Jews by the asperity of his expressions, had he said that the law was dead, he adopted a digression, and said, that we are dead to the law (202) To some indeed he appears to reason from the less to the greater: however, as I fear that this is too strained, I approve more of the first meaning, which is simpler. The whole argument then is formed in this manner “The woman is bound to her living husband by the law, so that she cannot be the wife of another; but after the death of her husband she is loosed from the bond of his law so, that she is free to marry whom she pleases.”

Then follows the application, —
The law was, as it were our husband,
under whose yoke we were kept until it became dead to us:
After the death of the law Christ received us, that is, he joined us,
when loosed from the law, to himself:
Then being united to Christ risen from the dead,
we ought to cleave to him alone:
And as the life of Christ after the resurrection is eternal,
so hereafter there shall be no divorce.

But further, the word law is not mentioned here in every part in the same sense: for in one place it means the bond of marriage; in another, the authority of a husband over his wife; and in another, the law of Moses: but we must remember, that Paul refers here only to that office of the law which was peculiar to the dispensation of Moses; for as far as God has in the ten commandments taught what is just and right, and given directions for guiding our life, no abrogation of the law is to be dreamt of; for the will of God must stand the same forever. We ought carefully to remember that this is not a release from the righteousness which is taught in the law, but from its rigid requirements, and from the curse which thence follows. The law, then, as a rule of life, is not abrogated; but what belongs to it as opposed to the liberty obtained through Christ, that is, as it requires absolute perfection: for as we render not this perfection, it binds us under the sentence of eternal death. But as it was not his purpose to decide here the character of the bond of marriage, he was not anxious to mention the causes which releases a woman from her husband. It is therefore unreasonable that anything decisive on this point should be sought here.