Codex S1 (or MS1; formerly Codex Sassoon 1053 and also Safra, JUD 002) is a Masoretic codex of the Hebrew Bible dated to the 10th century. It is considered as old as the Aleppo Codex and a century older than the Leningrad Codex (1006), the earliest known complete Hebrew Bible manuscript. The Aleppo Codex was missing 40% of its leaves when it resurfaced in Israel in 1958, while in Codex S1 12 leaves are completely missing and hundreds more are partially lost. The scribe of S1 was unusually sloppy, frequently forgetting punctuation, diacritical marks, and vowels; he also errs in his consonantal spelling on dozens of occasions. has announced a forthcoming critical edition of S1's masora magna. Name S1 is named after its previous owner David Solomon Sassoon (1880-1942). He also owned other important manuscripts, including the 10th century Damascus Pentateuch (Sassoon 507), which is now at the National Library of Israel in Jerusalem. Internal Features S1 is written with three columns to every page. The masora parva is complete, but the masora magna only appears on a few pages. Diacritical marks including the dot marking a shin or sin, the dagesh, the maqef, and the paseq are frequently missing. When a vowel is repeated on consecutive consonants, S1 often shows only the first. As a general rule, alephs receive an ordinary shva instead of a hataf vowel. In cases of disagreement, S1 agrees with the tradition of Ben Asher 40% of the time, with Ben Naphtali 20% of the time, and with neither 40% of the time. Ga'ya in an open syllable is marked less frequently that in the Aleppo Codex. The sof passuq is sometimes forgotten at the end of verses. History and Provenance S1 includes an incomplete masora magna (ad f. 452), apparently added by a later scribe, which refers to Aaron ben Moses ben Asher and the Aleppo Codex. It was carbon dated to the late 9th to early 10th century by its current owner, Jacqui Safra. It measures 12 x 14 inches, with a simple 20th-century leather binding. In the first centuries of its existence, the book switched hands throughout the Middle East, passed along from owner Khalaf ben Abraham to Isaac ben Ezekiel al-Attar, and then to his sons Ezekiel and Maimon. In the 13th century, it was dedicated to a synagogue in Makisin, now present day Markada (مَرْكَدَة), in Al-Hasakah Governorate, Syria. After