Calvin, John. Institutes of the Christian Religion. Translated by Ford Lewis Battles. I used the version available from AGES Digital Library, though I also have a hardcopy.
2.8.10, to understand you may need to refer to the Institutes and read this in context, on the Ten Commandments, Calvin says,
But why did God, as it were by half commandments, signify through synecdoche what he willed, rather than express it? While other reasons are also commonly given, this one especially satisfies me: the flesh ever tries to wash away the foulness of sins, except when it is palpable, and to overlay it with plausible excuses. Hence, God has set forth by way of example the most frightful and wicked element in every kind of transgression, at the hearing of which our senses might shudder, in order that he might imprint upon our minds a greater detestation of every sort of sin. In appraising our vices we are quite often deceived by this into making light of those which are somewhat concealed. The Lord disabuses us of these deceptions when he accustoms us to refer the whole mass of vices to these categories which best represent how heinous each kind is. For example, when called by their own names, we do not consider anger and hatred as things to be cursed. Yet when they are forbidden under the name “murder,” we better understand how abominable they are in the sight of God, by whose Word they are relegated to the level of a dreadful crime. Thus moved by his judgment, we ourselves become accustomed better to weigh the gravity of transgressions, which previously seemed light to us.
What Calvin does with the sixth commandment we could do with each of the commandments.