John Chrysostom

For what took place was not the natural thing,-their being injured by things profitable. And this is why he says "And the commandment, which was ordained to life, I found to be unto death." He does not say, "it was made," or "it brought forth" death, but "was found," so explaining the novel and unusual kind of discrepancy, and making the whole fall upon their own pate. For if, he says, you would know the aim of it, it led to life, and was given with this view. …

Homily on Romans 12 ↗

Theophylact of Ohrid

The words "I died" should be understood in two ways — both thus: "I sinned," and thus: "I became liable to greater punishment," for which not the law is to blame, but the one who heeds it. Consider, for example: someone is sick and does not realize that he is sick; then a physician comes to the sick man and reveals to him that he is sick, and that he ought to abstain from such-and-such food, as it aggravates the illness; the sick man did not listen to the physician and died. …

Commentary on Romans ↗

Thomas Aquinas

Then he concludes from the comparison between the two states the outcome of the law, saying that the commandment that was ordained to life . . . was found according to the intention of the lawgiver; second insofar as it pertains to the honesty and devotion of the one subject to the mandate: I gave them my statutes and showed them my ordinances by whose observance man shall live (Ezek 20:11) proved to be an occasion unto death to me, i.e., through sin which existed in man: his food is turned in his stomach, it is the gall of asps …

Commentary on Romans ↗