(A.D. 500-900)
Medieval scribes who employed a standardized form to produce the Masoretic Text, which is the basis for the Hebrew Bible used today, the Biblia Hebraica Stuttgartensia (BHS).
(The Origin of the Bible: Newly Updated by F. F. Bruce, J. I. Packer, Philip W. Comfort, and Carl F. H. Henry, 2020. Texts and Manuscripts of the Old Testament by Mark R. Norton, Page 155-156,175)
The work of the Masoretes
Biblical Hebrew is written without vowels, so as ancient Hebrew was being forgotten as Hebrews began speaking Aramaic, Greek, and Latin, the Masoretes worked to standardize the Hebrew text against a normative text, standardize punctuation and vowel patterns, and preserve the system of vocalization. The annotations inserted at the margin or after the text that marked irregular forms, abnormal patterns, and the number of times a form or word was used are called Masora, "tradition."
Masoretic standardization was practiced by identifying one text as normative, copying carefully from that text, and correcting existing texts by the normative text. Over a thousand year period starting early in the New Testament period, the next stage in transmission was the standardization of punctuation and vowel patterns (as Hebrew was written with only consonants).
A long series of Masoretes provided annotations known as Masora ("tradition"), including defining irregular forms, abnormal patterns, and the number of times a form or word was used as margin or foot notes and also a system of vocalization after insertion of vowels had been prohibited.
Oral tradition differed between Babylon and Palestine, but the Tiberian Masoretes provided the most complete and exact system. The earliest dated usage is a codex of the Prophets from the Karaite synagogue of Cairo (A.D. 896). Today, Biblia Hebraica Stuttgartensia is constructed on the basis of the Tiberian Masoretic tradition.
The Origin of the Bible: Newly Updated by F. F. Bruce, J. I. Packer, Philip W. Comfort, and Carl F. H. Henry, 2020. Texts and Manuscripts of the Old Testament by Mark R. Norton, Page 175)