Someone didn't like me pointing out that Christianity is inescapably Jewish in its content due to the Scripture of the First Testament being not only considered Scripture by Christians but the insights and thoughts contained in them comprise a large part of Christianity. The accusation is, of course, theft, of the adoption and interpretation of the Jewish Scripture by those who didn't originate them, the despised Christians.
But that ignores a fact about, not only the Jewish Scriptures, but about every piece of literature that has ever been read by those who didn't write them. Jews of the time of Jesus who read Isaiah or Leviticus or Exodus or Judges were as much adopters of those earlier writings as the first Gentiles who may have been introduced to them by Paul or the Jerusalem Community. Paul called himself a Jew, a Pharisee, one who had some kind of legal authority from before his conversion, an enforcer of one orthodox version of Jewish interpretation. James, one of the named leaders of the earliest Church in Jerusalem is believed by some of the earliest accounts of him to have had some kind of position at The Temple.
Even within Judaism near and at that time there were different religious sects which all used the same scriptures, coming to different views of them, no doubt claiming to some level of authenticity which their rivals didn't have. The writings that give us the thinking of Hillel is set in opposition to that of Shammai. Which of those Rabbis stole the Jewish Scriptures from those who had an authentic claim to them? Which of the various sects and factions that Jesus contended with in the Gospels had the authentic claim to the scriptures he cited and referred to? Which of the different and internally varied sects of Judaism today is most authentic? If, for example, you believe the Orthodox are based on some belief that they are an authentic continuation of ancient traditions going back to the origins of it, I have a feeling you'd be in for a fight on that point. And Orthodoxy is far from homogenous.
If you want to put it in other terms, they're no more an example of ancient tradition than the revived Tridentine Masses of the absurd present-day Catholic far right* are even a reproduction of the early Tridentine liturgy. It, itself, is a modern innovation, I believe the books used for it today date from the early 1960s the most recent in a line of liturgical reforms that starts in the early modern period.
The fact is that all later readers and interpreters of the Jewish Scriptures, Jews, Christians, Muslims, etc. up to and those who use them today, are doing the same thing. They are reading things that other people wrote thousands of years ago, in contexts and cultures and traditions and individual points of view, they are understanding or asserting their understanding of those texts in terms of their own personalities formed from whatever those are formed.
All of us are "stealing" the words of whoever wrote those scriptures, if that's how you insist on putting it. None of us has a direct line into the minds of the writers except those writings, all of us have an equal claim to the possibility of understanding them. That is especially true of the most poetic, or prophetic of them. None of us has a superior claim on them just as different scholars of an author have different ideas about what their writings mean. There can be more obviously valid arguments about claims to the authors' meaning based in history and comparative literature, if someone claims something which the author clearly didn't intend, that can be known but even that, in the end depends on whoever you want to persuade to your thinking finding it persuasive. And some of that does fall back on the authors. If, for example, the author of Isaiah didn't want someone using his images of the Holy Mountain of God to mean heaven, whoever wrote it could have written that in expository prose instead of poetry. But if they did, I'll bet no one would read it now.
If you want to get more of a feeling of what I'm saying, in a form that's more entertaining, you might read Jane Langton's Emily Dickinson is Dead, #5 of her Homer Kelly mysteries. I love the fist fight that breaks out in the English Department office between Homer Kelly and the Chairman, it brings me back to my college years and the various, vicious wars within the various departments. Those in the music department were particularly vicious. The one I recall with particular vividness didn't end till the last of one faction retired and his students graduated. I believe the faculty there now wouldn't know anything about it, they probably have their own wars.
* I have to smile when I hear young right-wing Catholic fanatics who yearn for the return of a Latin rite they never experienced as children because it stopped being used well before they were born. I remember it well as a lived experience and it was far from a holy one. I remember looking down from the choir loft as a child as the priest raced through the Latin text that he and maybe one or another of the hundred and fifty or so people there understood rather imperfectly. The pious in the congregation were ignoring the mass as they said their rosary, most of the others mouthed the Latin responses which I have a feeling many of them didn't understand, though those who did, they were the only Latin words they did know.
Contrary to what the present day romantics of the Tridentine rite might think, Gregorian Chant had hardly any place in it, apart from one badly botched and altered version of the Kyrie (the Kyrie Orbis factor, in most of the churches as I recall), and that, of course, was to a Greek text. I doubt most of the people who intoned it even realized they were singing in Greek.
Update: Yeah, it was this one. This is the Youtube version that sounds most like what I remember.