For when ... - The illustration in this verse and the following is designed to show more at length the effect of the Law, whenever and whereever applied; whether in a state of nature or of grace. It was always the same. It was the occasion of agitation and conflict in a man’s own mind. This was true when a sinner was under conviction; and it was true when a man was a Christian. In all circumstances where the Law was applied to the corrupt mind of man, it produced this agitation and conflict. Even in the Christian’s mind it produced this agitation Romans 7:14-24, as it had done and would do in the mind of a sinner under conviction Romans 7:7-12, and consequently there was no hope of release but in the delivering and sanctifying power of the gospel Romans 7:25; Romans 8:1-3.
In the flesh - Unconverted; subject to the controlling passions and propensities of a corrupt nature; compare Romans 8:8-9. The connection shows that this must be the meaning here, and the design of this illustration is to show the effect of the Law before a man is converted, Romans 7:5-12. This is the obvious meaning, and all the laws of interpretation require us so to understand it.
The motions of sins - (τα παθήματα ta pathēmata.) This translation is unhappy. The expression “motions of sins” conveys no idea. The original means simply the passions, the evil affections, the corrupt desires; see the margin. The expression, passions of sins, is a Hebraism meaning sinful passions, and refers here to the corrupt propensities and inclinations of the unrenewed heart.
Which were by the law - Not that they were originated or created by the Law; for a law does not originate evil propensities, and a holy law would not cause sinful passions; but they were excited, called up, inflamed by the Law, which forbids their indulgence.
Did work in our members - In our body; that is, in us. Those sinful propensities made use of our members as instruments, to secure gratification; Note, Romans 6:12-13; compare Romans 6:23.
To bring forth fruit unto death - To produce crime, agitation, conflict, distress, and to lead to death. We were brought under the dominion of death; and the consequence of the indulgence of those passions would be fatal; compare the note at Romans 6:21.