Did Emperor Justinian Actually Intervene in How Yahudim Read Their Own Sacred Writings Inside Their Synagogues?
553 CE · Emperor Justinian I · Novella 146
What the ancient record says
Yes, one of the most extraordinary documents in the collection. By 553 CE the emperor regulated not only office, marriage, property, synagogue construction, and conversion, but issued legislation on how sacred writings could be read inside Yahudi congregations.
The preface says a dispute existed among Yahudim themselves, some wanted the writings read in Lashon Qanaʿan (Hebrew), others wanted a Greek translation so listeners could understand; the disagreement was brought before his government, and the emperor declared he would not permit it to continue without an imperial ruling, stepping directly into an internal Yahudi dispute over how their own sacred writings were publicly read. Ruling: he permitted synagogue reading in Greek, Latin, or another locally understood language, justified by listeners understanding what was read.
Did he completely ban Lashon Qanaʿan (Hebrew)? No, Novella 146 does not say "Hebrew is forbidden"; it protects the ability of those who want a translation to hear Greek/another language and prevents synagogue authorities from stopping them; "Justinian completely banned Hebrew Scripture" goes beyond the law.
But he still entered the synagogue's textual practice, an enforceable ruling on the language and interpretation of sacred-text reading.
Read it for yourself. Justinian, Novella 146, Preface + Chapter 1.
Evidence strength: Direct imperial legal evidence.