I don't know of any Reformed writer in support of the LXX over against the MT. Episcopius, a Remonstrant and Vossius, a Libertine seemed to have been sympathetic to LXX. In a book of the second half of the 17th century I recently got interested in written by Oomius, I read the following exemplary exposition of the default Reformed position of that time of the non-authenticity of the LXX (translation by ChatGPT):
3. In the translated texts of all languages, the authority pertains only to the matters and meaning faithfully expressed, but not to the words and modes of speech used to express them.
The reason is that none of these texts were written or approved by a prophet, apostle, or any infallible council and recommended to the Church of God. Rather, they have all been produced and written by human diligence and effort, according to human judgment, by people subject to error.
This is readily admitted concerning the texts of all other editions and languages, but it is denied with regard to the Greek version of the Old Testament and the common Latin translation.
a. Concerning the Greek edition or translation of the Old Testament:
Most of the early Church Fathers or teachers believed that when Ptolemy, son of Lagus (or as others say, Philadelphus), ruled in Egypt, at his request to the Jewish high priest Eleazar, six men from each tribe of Israel—learned in Hebrew and Greek, totaling seventy-two—were sent to Egypt. There, they translated the five books of Moses (or, as others claim, all the books of the Old Testament) from Hebrew into Greek in the space of seventy-two days.
This legend is also read in the Jewish Talmud. Justin states that each was placed in a separate chamber; Epiphanius says that there were two by two. They each made their translations independently, and when compared afterward, they were found to match perfectly—even without differing in a single word.
This supposedly confirmed to the early Church Fathers that the translation was divinely inspired, especially since the Apostles and Evangelists often quoted the Old Testament more from this version than from the original Hebrew. Because the early Latin and common edition were first printed from it, the Roman Church began to consider it authentic.
But just as it is certain that the Greek translation of the Old Testament is not, and never was, authentic in terms of words and modes of speech (but only in terms of matters and meaning, insofar as they were faithfully rendered from the Hebrew), so it is also certain that the edition, if not entirely lost, is at least corrupt and depraved. Therefore, it can no longer be recognized as the true version of the seventy-two translators.
The aforementioned wonderful story of the translation, borrowed from one Aristeas and repeated by Josephus (writing against Apion) and by Philo the Jew, is embellished and has been powerfully refuted with sound reasons by Joseph Scaliger, and after him also by Johannes Wowerius and Rivetus. These show on what grounds Heinsius judged that the Hellenists formed their opinion about the seventy-two men and their harmonious agreement.
Thus, this translation is not to be regarded as authentic—not because of its miraculous origin (which is merely assumed and embellished), nor because its texts are sometimes cited in the New Testament. For the Apostles and Evangelists did not thereby intend to endorse or equate them with the original Hebrew text. I leave aside how some elevate it as superior—even in print—such as Episcopius and others, and more recently with greater presumption than solidity, by Isaac Vossius.
Vossius, whose learning is otherwise highly praised, is disdainful of anyone not immediately swayed by his weak arguments, branding them as foolish, nonsensical, ignorant, or at best half-learned. This is surely a very clever and elegant method of disputing!
But since they (the Apostles and Evangelists) wrote in Greek, they used the Greek translation, which was known especially among the dispersed Jews. They cited it only insofar as it aligned with the Hebrew truth or conveyed a sentiment that pleased them or the Holy Spirit—while letting the deviations from the original Hebrew be.
And who can confirm and prove to us that the New Testament passages cited were indeed all quoted from the Septuagint translation? For no one without serious cause would deny that some early Christians—though pious—might have unfaithfully conformed certain Septuagint passages to match the Apostolic words of the New Testament where they otherwise differed.
For who does not know how greatly the Septuagint translation has changed, just like the Latin one? The same zeal that led to the forgery of the Sibylline Oracles to convert pagans also likely led to the conforming of Septuagint passages to the New Testament.
Therefore, once these supports for the authority of the Septuagint are removed, the great authority attributed to it falls as well, and it can claim no more authority than other translations.
Let this suffice for now as a brief statement.
Those who desire a more thorough explanation may consult the works written on this subject—especially beyond the already mentioned Sixtinus Amama, Ussher, Rivetus, Spanheim (though they speak briefly about the translation’s authority and completeness), and what is to be held concerning it: Hottinger, Owen, Vogelsangius, Christianus Schotanus (whom Vossius refutes learnedly), Leusden, David Christiani—a Lutheran theologian—and many others who have written against the Papacy.
Some of them are especially mentioned above, particularly among the more recent authors.
