Jerome's introduction to the Vulgate

A fascinating read here:

A sampler

The present translation follows no ancient translator, but will be found to reproduce now the exact words, now the meaning, now both together of the original Hebrew, Arabic, and occasionally the Syriac. For an indirectness and a slipperiness attaches to the whole book, even in the Hebrew; and, as orators say in Greek, it is tricked out with figures of speech, and while it says one thing, it does another; just as if you close your hand to hold an eel or a little muræna, the more you squeeze it, the sooner it escapes. I remember that in order to understand this volume, I paid a not inconsiderable sum for the services of a teacher, a native of Lydda, who was amongst the Hebrews reckoned to be in the front rank; whether I profited at all by his teaching, I do not know; of this one thing I am sure, that I could translate only that which I previously understood.

Good for Jerome. I translated in order to seek what I could understand. I am suspicious of understanding in case I turn it into something else over which I think I have power. 

Re the Psalms:

"Jerome had, while at Rome, made a translation of the Psalms from the LXX., which he had afterwards corrected by collation with the Hebrew text." ...His friend Sophronius, in quoting the Psalms to the Jews, was constantly met with the reply, “It does not so stand in the Hebrew.”

and later on some detail,

Long ago, when I was living at Rome, I revised the Psalter, and corrected it in a great measure, though but cursorily, in accordance with the Septuagint version. You now find it, Paula and Eustochium, again corrupted through the fault of copyists, and realise the fact that ancient error is more powerful than modern correction; and you therefore urge me, as it were, to cross-plough the land which has already been broken up, and, by means of the transverse furrows, to root out the thorns which are beginning to spring again; it is only right, you say, that rank and noxious growths should be cut down as often as they appear. And so I issue my customary admonition by way of preface both to you, for whom it happens that I am undertaking the labour, and to those persons who desire to have copies such as I describe.  

ancient error is more powerful than modern correction

Well well - I don't think I am correcting, but I am challenging all the condensed theology I was taught in my early days.