Rather than try to defend such a rash assertion, I think it would be better to acknowledge that many Biblical prophecies and images, and especially in Revelation, are polysemous. In Revelation 12, the Great Sign of the Mother in the sky, is referring the Mary the Mother of the Messiah (primary meaning, since her motherhood, and the identity of her newborn Infant as Messiah, are both clearly referenced)) AND Israel/Daughter Zion, AND the Church founded by Christ (secondary or derivative, dependent upon the primary.) These three meanings frequently overlap, and never more profoundly than here at Rev. 12.
"Free of error" in this case --- the mystical writings --- means only that the parts that touch on doctrine, can be interpreted in a sound and orthodox way, RARELY as literal doctrinal formula (VERY RARE in mystical writings!)--- or as an illustration by analogy, or by allegory, or by imagery, or by way of a conditional truth (e.g. IF 'this' happens, then 'that' will happen.)
There are some outright errors in the writings of some mystics. These are not endorsed by the Church. Even if the mystic in question is a canonized saint, that does not mean all their writings are perfect in all respects! Some of them are too ambiguous to yield a judgment of their accuracy. (Ambiguity is a characteristic of any Bible passages too, as we have seen.
(E.g. how many people were at the foot of the Cross?)
(E.g. "And what the LORD doth require of thee: Only to do justly, and to love mercy, and to walk humbly with thy God." What does "only" mean in this passage? You don't have to believe in Christ?")
E.g. "See how a person is justified by works and not by faith alone." (James 2:24) What???)
"Free of error" does not mean that that it is part of the Deposit of Faith, comprising the truths that were handed on to us by he Apostles. No "new truths" of this sort have emerged "de novo," nor could they emerge, after the Apostolic Age, which closed at about the end of the First Century AD.
The picture is of a woman at a well. Sort of off toward the corner there is a raised and very faded figure of (probably)_ an angel ---"probably" an angel, since the figure is raised as if in mid-air; and there's a faded line showing something like starburst occurring in or on the woman.
The art experts say it *could* be the Samaritan woman at the well, but not likely, since such pictures usually center on Christ talking to her, which is not shown at all.
Since the faded figure is probably an angel, and since something is happening within the woman (starburst) another view --- and this is only a point of view --- is that it is the Annunciation, the angel is Gabriel, and the woman is Mary showing he (symbolically) conceiving Christ within her.
Scripture says the angel came "in" to speak to Mary, while some interpret to mean she must have been inside her house. Others translate this is "came INTO her presence." Of the 24 variant translations listed at Bible Hub, they are about equally divided between coming "in" and not mentioning "in" at all.
So I don't think it can be determined whether this passage is saying the angel came into her house or just into her presence. Not only that, bu Jewish law considers your courtyard to be part of your house --- this is important for hakachic regulations which say you can take only so many steps outside of your "house" on the Sabbath. So if Mary had a well in her courtyard, she would still be considered (by Jewish law) to be in her house, and the angel could come in to her (at the well) without implying that the well was located in the middle of her living-room :o) ..
All this is secondary. Whether or not Mary was portrayed on the mural at Dura Europos, she was certainly addressed as well as pictured on the underground tufa walls at, e.g. the Catacomb of Priscilla in Rome. Being pictured is a form of dulia-- simple honor, neither more nor less.
This WAS going to be a short kite!
or As when a suit, courting his beloved, says "You are my ONLY love," he manifestly does not mean that he doesn't love his father and mother, or that he doesn't love God. He's just trying to express an exalted view of this beloved woman. No reasonable person would think otherwise.
Similarly, no Christian--- and no scholar, looking over the whole corpus of Ephrem's work --- could reasonably conclude that Ephrem thought Mary was the literal, sole advocate of sinners. That would take him clear out of Christianity; whereas his poetic work is, in fact, highly Christocentric.
I myself am, in fact, an advocate for sinners. I pray for sinners daily. And this is the ONLY way that Mary, as a human persona d as a disciple of Christ, can "advocate" for sinners: by commending them to Christ.
Back to the beans. Adieu.
To begin with...the mere fact he has written an entire book devoted to the "glories of Mary" is mind-boggling in itself.
The quotes in the book, and there are more than one, lend support to my position that these writers were placing their hope and trust in Mary.
St. John of Da mascus expresses the same thing when, address ing the blessed Virgin, he says to her: Oh Lady, in thee I have placed all my hope, and with firm confidence I look to thee for my salvation,
f St. Thomas says that Mary is all the hope of our salvation.
J St. Ephrem explains: Oh most holy Virgin, receive us under thy protection, if thou wilt see us saved, since we have no other hope of being saved but through thee.
Paul and John would have recoiled at such statements. I find it telling that in all of their writings no such "devotion" or reliance was ever accorded to Mary as there are in more than one roman catholic writing.
To your point that the "mystics" sometimes made errors.
This new and improved translation of "The Glories of Mary, " having been duly examined, is hereby approved of.
John, Archbishop of New York NY, Jan 21st 1852
This illustrates the problem with roman catholicism's reliance upon tradition. When the writer says something catholics like he's a great guy and accepted. When the same writer's works are really examined and contradictory positions to the Bible are espoused the catholic retreats to "it's not doctrine" or they made errors.
However, in this case the Archbishop of NY approved this book and it's contents and message. This would tell me he has found no doctrinal issues with the book. Being an Archbishop I would imagine he had a pretty good grip on roman catholic beliefs.
Catholics cannot have it both ways.