ben Naphtali was a rabbi and Masorete who flourished about 890-940, probably in Tiberias. Of his life little is known. His first name is in dispute. Some medieval authorities called him "Jacob"; two Tchufut-Kalè manuscripts have "Moses b. David"; a third contains his autoepigraph, which unfortunately is incomplete, only "ben David ben Naphtali" remaining.
ben Naphtali and ben Asher 
ben Naphtali wrote a Bible with vowels, accents, and Masorah, wherein he differed in some respects from his contemporary and rival, Aaron ben Moses ben Asher. This Bible codex has not been preserved, but the differences between its author and ben Asher are found in more or less complete Masoretic lists and in quotations in David Ḳimḥi, Norzi, and other medieval writers. These lists are printed in the rabbinical Bibles, in the texts of Baer-Delitzsch and of Ginsburg, and in the latter's Masorah, vol. iii. The differences between ben Naphtali and ben Asher number about 875, nine-tenths of which refer to the placing of the accents מתג and געיא. The remaining ones have reference to דגש and רפה, to vowels, accents, and consonantal spelling. For a list of differences between ben Naphtali and ben Asher, see ben Naphtali at the Jewish Encyclopedia.
Relation of Both to Received Text 
The differences between the two Masoretes do not represent solely personal opinions; the two rivals represent different schools. Like the ben Ashers there seem to have been several ben Naphtalis. The statement of E. Levita (Mas. ha-Masoret, ed. Ginsburg, p. 144), that the Westerns follow ben Asher, and the Easterns ben Naphtali, is not without many exceptions. Thus, for instance, in the difference concerning I Kings iii. 20 (see ben Naphtali, No. 7), the Westerns are said to agree with ben Naphtali, while the Easterns follow ben Asher. The rule of ben Naphtali given under No. 5 is followed in all MSS. and printed editions, in the words ביקרותיך (Ps. xlv. 10) and ליקהת (Prov. xxx. 17), etc. The Masoretic lists often do not agree on the precise nature of the differences between the two rival authorities; it is, therefore, impossible to define with exactness their differences in every case; and it is probably due to this fact that the received text does not follow uniformly the system of either ben Asher or ben Naphtali. The attempt is likewise futile to describe the one codex as Western or Eastern.
Jewish Encyclopedia bibliography 
- Diḳduḳe ha-Ṭe'amim, ed. Baer and Strack, p. 11;
- Harris, Jew. Quart. Rev. i. 250;
- Ginsburg, Introduction to the Masoretico-Critical Edition of the Hebrew Bible, pp. 241 et seq.
Other sources 
- Kahle, Paul, Masoreten des Westens: 1927, repr. 1967 and 2005