Did Justinian Claim the Septuagint Translators Miraculously Produced the Same Text?

Novella 146, Ch. 1 · 553 CE

What the ancient record says

Yes, he repeats an old tradition: the translators were separated while working and nevertheless produced an agreeing translation, using this as part of his argument for the translation's authority. Does that prove the story historically happened exactly that way?

No, a perfect example of the difference between what a source says and what it independently proves about a much earlier event: Novella 146 proves Justinian repeated and promoted this tradition in 553 CE; it does not by itself provide contemporary evidence from the original translation period proving the miraculous account. Repetition across centuries is not automatically independent confirmation, a 6th-century emperor repeating a much older story proves the story was circulating and accepted by him, not every detail of the original event.

Beyond question: he used the tradition to support the authority of the Septuagint over the ancestral Lashon Qanaʿan (Hebrew) writings as heard through Greek translation.