He writes concerning the Westminster Confession of Faith (p. 81):
If the Westminster confession argues the necessity of translation and the propriety of the use of Scripture by the unlearned, it also insists upon the priority of the Hebrew and Greek originals of the books of the Bible and ultimately lodges all authority in the text as preserved in the ancient languages. The Hebrew and Greek texts are the "authentic" Scriptures that were "immediately inspired by God, and by his singular care and providence kept pure in all ages." "Final appeal" in all religious controversy, therefore, must be to the text in the original languages rather than to translations. The detail there, is once again greater than that of previous confessions, but it cannot be claimed that we have entered the realm of dogmatic system. There is no elaboration or discussion distinguishing between "words" (verba) and "substance" (res) such as appears in the systems of the day and no discussion of the autographa. The emphasis of the confession is simply upon the original language texts currently known to the church.
Muller quotes the Formula Consensus Helvetica on p. 84:
God, the supreme Judge, not only took care to have his word, which is the "power of God unto salvation to everyone that believes" (Rom. 1:16), committed to writing by Moses, the Prophets, and the Apostles, but has also watched and cherished it with paternal care ever since it was written up to the present time, so that it could not be corrupted by the craft of Satan or fraud of man.
Muller comments then:
The position is very similar to the one taken at the beginning of the Westminster Confession, although more detailed, and it is little different from statements concerning the gift and preservation of the Scriptures in Reformed dogmatics as early as Calvin's Institutes and Bullinger's Decades.
He's saying that this was long time the position of believers on the doctrine of preservation. And you can see that there was a connection in their minds between inspiration and preservation. Both of them were Divine.
He writes concerning John Owen on p. 134:
He (Owen) had not, it is true, predicated his doctrine of Scripture as Word on his ability to prove the perfection of the text. Rather, like Turretin and the other orthodox, he had done precisely the opposite: he assumed the authority, infallibility, and integrity of the text on doctrinal grounds.
On p. 231, he writes concerning the divinity of Scripture:
It ought be clear that the Reformers assumed a divine power at work in the writing and preservation of Scripture that, in concert with the efforts of the human authors and with scribal preservers of the text, had assured the availability of and authoritative Word of God in and for the life of the church.
He writes on p. 294 concerning the miracle of preservation:
On a lesser level of significance but nonetheless useful to the defense of the text against its detractors are the "extrinsic" arguments, which are divided by Leigh and others into two basic categories: miracle and testimony. The miracles can be miracles of "confirmation" as those performed by Christ and the apostles to manifest the truth of their words, or miracles of "preservation" like the providential care by which God preserved Scripture from all efforts of tyrants and evil men "to suppress and extinguish the word."
Muller gets to a section on the doctrine of preservation of Scripture. He writes on p. 433:
By "original and authentic" text, the Protestant orthodox do not mean the autographa which no one can possess but the apographa in the original tongue which are the source of all versions. The Jews throughout history and the church in the time of Christ regarded the Hebrew of the Old Testament as authentic and for nearly six centuries after Christ, the Greek of the New Testament was viewed as authentic without dispute. It is important to note that the Reformed orthodox insistence on the identification of the Hebrew and Greek texts as alone authentic does not demand direct reference to autographa in those languages; the "original and authentic text" of Scripture means, beyond the autograph copies, the legitimate tradition of Hebrew and Greek apographa.
At the end of that page he writes:
The case for Scripture as an infallible rule of faith and practice . . . . rests on an examination of the apographa and does not seek the infinite regress of the lost autographa as a prop for textual infallibility.
In that last part of that sentence, which I wanted to draw your attention to, Muller is speaking about what A. A. Hodge and B. B. Warfield did with the Westminster Confession. They are the ones who use the "lost autographa as a prop for textual infallibility." He has a long footnote documenting and commenting on that statement, which reads:
A rather sharp contrast must be drawn, therefore, between the Protestant orthodox arguments concerning the autographa and the views of Archibald Alexander Hodge and Benjamin Breckinridge Warfield. . . . Those who claim an errant text, against the orthodox consensus to the contrary, must prove their case. To claim errors in the scribal copies, the apographa, is hardly a proof. The claim must be proven true of the autographa. The point made by Hodge and Warfield is a logical leap, a rhetorical flourish, a conundrum designed to confound the critics---who can only prove their case for genuine errancy by recourse to a text they do not (and surely cannot) have.
He writes on p. 435:
Turretin and other high and late orthodox writers argued that the authenticity and infallibility of Scripture must be identified in and of the apographa, not in and of lost autographa.
He continued on p. 437:
The Reformed orthodox insisted on the providential preservation of Scripture in its integrity and the consistent care taken by the church throughout history to care for the text. This assumption of integrity refers, moreover, not to the versions but to the Hebrew and Greek sources on which all versions must be based.
On the top of p. 443, summarizing a section, he writes:
The Reformed orthodox do, thus, engage in a concerted textual effort to maintain their doctrine of the purity and perfection of the text of Scripture.
Muller talks about the Johannine Comma, the text of 1 John 5:5-8. Here are sentences in favor of this trinitarian text:
Of the early sixteenth-century editions of the Greek text of the New Testament, the Complutensian Polyglott (1504-1514) includes the phrase. . . . Later editions [of Erasmus] (1527 and 1536) also include the "comma." Erasmus' third edition was followed on this point by both Stephanus (1546, 1549, 1550) and Beza (1565; with annotations, 1582). . . . Reformed theologians, following out the line of Erasmus, Stephanus, and Beza, tended to accept the text as genuine and, indeed, to use it as an integral part of their trinitarian theology. . . . In the theological works of the seventeenth-century orthodox---on the model provided by Calvin and Beza---the Johannine "comma" appears frequently, without question or comment, as one Johannine text among others cited in a catena of texts from the Gospel, the Apocalypse, and the epistles as grounds of the doctrine of the Trinity. Often the phrase is simply cited without comment as a supporting text, while some of the high orthodox writers note that it was cited by Cyprian---thus, by implication, refuting the arguments concerning its extremely late date. . . . Turretin noted that Erasmus had located the passage in a "most ancient British codex" and that "most praiseworthy editions, the Complutensian, the Antwerp, Arias Montanus, R. Stephanus, and Walton, which have all utilized the best codices, have the phrase.
At the very end of the book on p. 541, Muller makes this very interesting statement that is tell-tale for today:
All too much discussion of the Reformers' methods has attempted to turn them into precursors of the modern critical method, when in fact, the developments of exegesis and hermeneutics in the sixteenth and seventeenth centuries both precede and, frequently conflict with (as well as occasionally adumbrate) the methods of the modern era.
I especially include the last quote because of the common extrapolation that the 16th and 17th century theologians were actually involved in textual criticism. This is sheer revisionist history.