Origen is sometimes used, but we find the same out-of-context quotes being extractred. Moreover, Origen is simply not the most reliable witness due to his many heterodox theological ideas that were banned by the Church.
Undaunted, some apologists have cited the Didaskalia Apostolorum, which is purported to have been written by the Apostles, as being supportive of the "works of the law = ceremonial law" concept. But not only does this document not identify who the writer actually is, or its date of writing, it is not cited by any of the Fathers or Councils as holding any authority whatsoever. Moreover, it contains many questionable statements, and some that are totally opposite from what we find in the Council of Trent and the Catholic Catechism. For all intents and purposes, it is a spurious document without the slightest credibility. Even at that, its argument for the ceremonial law is not that strong.
Next we come to the great Fathers, Augustine and Jerome. It is said that Jerome also sided with the "works of the law = ceremonial law" apologetic. I have in the past accepted this on the word of those who purport such, but I must say that no one has yet produced the citation from Jerome where he indeed says so, nor have they shown where Jerome rejects the moral law as being included in the "works of the law" formula. Even if Jerome did take such a view, this would be somewhat out of place, since no contemporary of his would have agreed. Chief among them is St. Augustine.
Commenting on Romans 7 Augustine writes:
Although, therefore, the apostle seems to reprove and correct those who were being persuaded to be circumcised, in such terms as to designate by the word "law" circumcision itself and other similar legal observances, which are now rejected as shadows of a future substance by Christians who yet hold what those shadows figuratively promised; he at the same time, nevertheless, would have it to be clearly understood that the law, by which he says no man is justified, lies not merely in those sacramental [ceremonial] institutions which contained promissory figures, but also in those works by which whosoever has done them lives holily, and amongst which occurs this prohibition: "Thou shalt not covet."
Is it possible to contend that it is not the law which was written on those two tablets that the apostle describes as "the letter that killeth," but the law of circumcision and the other sacred rites which are now abolished? But then how can we think so, when in the law occurs this precept, "Thou shalt not covet," by which very commandment, notwithstanding it being holy, just, and good, "sin," says the apostle, "deceived me, and by it slew me"? What else can this be than "the letter" that "killeth"? (On the Spirit and the Letter, NPNF, vol. 5, p. 93).
Notice that Augustine is well aware of the temptation some have in saying that the "Law" refers only to the ceremonial law. To avoid this temptation, Augustine tells us that Paul "would have it clearly understood" that he does not wish to confine "Law" to the ceremonies. One of Augustine's proof texts is Romans 7:7, where Paul says that the Ninth and Tenth commandments, which are concerned with the sin of coveting, are representative of the entire Law that condemns men in sin and cannot be relied upon to justify him.
The significance of this is that the law against coveting is a MORAL law, not a ceremonial law. We must conclude, then, that if Paul is saying that the moral law condemns him in sin, and therefore does not justify him, then it is the moral law that cannot justify; and it is the moral law that must be set aside. Obviously, it is not just the ceremonial law which needs to be set aside.
Romans 7 is such an important passage in helping us understand the issue of Justification. Unfortunately, I find many Catholic apologists simply ignoring Romans 7; or if they do address it, they twist it out of its context to make it coincide with their preconceived concept that "law = ceremony," totally dismissing the fact that Paul says that the "law" which must be set aside in order for man to be saved includes the moral precepts of Old Covenant Israel.
Not only does Augustine tell us this about Paul, but St. Thomas Aquinas has the same interpretation. Unfortunately, those who are trying to support the idea that "works of the law = ceremonial law" fail to quote the places where Aquinas denies that teaching, and instead they concentrate on the places where Aquinas appears to say that the law refers to the ceremonial law.
It is true that in one place, Aquinas' interpretation of Galatians 2:16, he says that the "works of the law" refers mainly to the ceremonies, but this is only because the verses immediately prior are clearly focusing on that one aspect of the law (cf., Galatians 2:11-15). But when Aquinas comes to Galatians 3:10-12 he is very careful to say that the "Law" which Christ came to set aside so that man can be justified refers to the WHOLE Law of Israel, the ceremonial law and the moral law. Here's what he says:
"Works of the Law" - Page 4