But you have a hard and stubborn heart is actually a prepositional phrase to be taken with the verb you are making your own punishment even greater, and means something like “in keeping with your hard and stubborn heart.” You are making you own punishment even greater is a word picture, the picture of a man treasuring up something for himself, only in this context it is punishment.
The sentence you have a hard and stubborn heart may be related to what follows as cause-effect—for example, “because you have a hard and stubborn heart, you are causing your judgment to be even greater.” In many languages one must avoid an expression such as “hard” in connection with “heart,” since the phrase “hard heart” frequently has quite a different meaning—“strong” or “brave,” for example. In some languages the equivalent idiom for hard and stubborn heart would be “your ears have no holes” (that is to say, “you will not respond to reason”). It is this refusal to reason which is the basic meaning of hard and stubborn heart. In some languages the only satisfactory equivalent of this emphatic expression is “because you are so completely stubborn.”
The word rendered punishment in the Good News Translation is the word translated “wrath” elsewhere. The reference, of course, is to the punishment God brings because of his wrath. It is normally not difficult to find a word for punishment, but it is difficult in some languages to speak of “making your punishment greater.” A more satisfactory equivalent may be “God will judge you more severely,” “God will cause your punishment to be stronger when he judges,” or “God will cause you to suffer even more when he judges.”
Day is spelled with a capital in the Good News Translation, inasmuch as in both Jewish and Christian thought this was a specialized term, referring to the final day on which God would bring his wrath and punishment on all evil doers. The Day when God’s wrath and right judgments will be revealed is in Greek a noun phrase, “in the day of wrath and the revelation of the righteous judgment of God.”
The passive expression will be revealed may be transformed into an active with God as the agent—for example, “the day when God will show his anger and judge rightly.” In some instances a reference to God’s anger, without indicating that it is anger against sin, could prove to be inappropriate and out of keeping with the context. Therefore, one may say “God’s anger against sin” or “God’s anger because people have sinned.”
Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on Paul’s Letter to the Romans. (UBS Handbook Series). New York: UBS, 1973. For this and other handbooks for translators see here .