Daniel wrote:But I personally feel the Middle Voice is in view here in Acts 13:48, though admittedly no major English translation renders it this way, i.e., “were appointing themselves.”
Daniel, you seem to be referring to the classical meaning of the middle voice, that the action of a verb in the middle voice in some way affects the subject. However, this is not reflexive. According to William Mounce in his grammar book
Basics of Biblical Greek, 25.13, "If the subject of the verb performs an action to itself, Greek requires the reflexive pronoun."
If the word "τετραγμενοι" is in the middle rather than the passive voice as you suspect then it would be "literally" translated as "were appointing for themselves into lasting life".
Now the NAS sometimes translates the verb as "established" ---- and the Greek "εις" (into) refers to a goal or purpose. So if you are correct that the verb is middle, one might translate the sentence "as many as established for themselves the goal of lasting life, believed." Congratulations! You may have hit upon Luke's true intention. This also contrasts well with the statement of Paul and Barnabus that the Jews considered themselves to be unworthy of lasting life. (vs 46)
It may be of interest to read what Greek scholar Henry Alford had to say about this verse in
Alford's Greek New Testament which he completed about the middle of the 19th century, and revised several times:
τετραγμενοι] The meaning of this word must be determined by the context. The Jews had judged themselves unworthy of eternal life:the Gentiles, as many as were disposed to eternal life, believed. By whom so disposed, is not here declared; nor need the word be in this place further particularized. We know, that it is God who worketh in us the will to believe, and that the preparation of the heart is of Him: but to find in this text pre-ordination to life asserted, is to force both the word and the context to a meaning which they do not contain. The key to the word here is the comparison of ref. I Cor. εις διακονιαν τοις αγιοις εταξαν εαυτους, with ref. Rom. αι οθσαι (εξοθσιαι) υπο του θεου τεταγμεναι εισιν : in both of which places the agents are expressed, whereas here the word is absolute.
Alford then, after quoting several interpretations in Latin, remarks:
There are several other renderings, but so forced as to be mere caricatures of exegesis: see Meyer. It may be worth while to protest against all attempts to join επιστευσαν with εις ζωην αιωνιον, which usage will not bear. Wordsworth well observes that it would be interesting to enquire what influence such renderings as this of præordinati in the Vulgate version had on the minds of men like St. Augustine and his followers in the Western Church in treating the great questions of free will, election, reprobation, and final perseverance: and on some writers in the reformed churches who, while rejecting the authority of that version, were yet swayed by it away from the sense of the original here and in ch. ii.47. The tendency of the Eastern Fathers, who read the original Greek, was, he remarks, in a different direction from that of the Western School.