Another Jewish source missionaries will site claiming that "ancient Jewish sources" interpreted the servant in Isaiah 53 as "the" messiah (and not the Jewish nation) is יפת בן עלי הלוי / Yefet ben Ali (Yefet, son of Ali).
Jews for Jesus does not cite Yefet ben Ali on Isaiah 53, but other missionaries do -- and again the source yet again appears to be the 19th century Christian book The 53rd Chapter of Isaiah According to Jewish Interpreters by Driver and Neubauer which is discussed in this blog post. This book was the brainchild of Edward B. Pusey, an English Christian missionary, and a canon of Christ Church Cathedral in Oxford, from 1828 until his death. Pusey's goal was to missionize the Jews. The infamous book he sponsored (regarding Isaiah 53) has been used to evangelize the Jews for well over a hundred years. "the way whereby our L-rd's kingdom is to be enlarged, plainly is by Missionaries," wrote Pusey.
Would Christians hold up Joseph Smith, founder of the Mormons, as a great expert on Christianity?
Of course not.
Normative Christianity rejects the teachings of Joseph Smith.
Yet missionaries hold up Jewish apostates as if they are some reputable Jewish source, and this is the case with Yefet ben Ali as quoted (selectively as we will see) by missionaries.
So who was Yefet Ben Ali?
He was not a "Rabbi."
He was not a "Rabbinical" source.
He was a 10th century (C.E.) Karaite.
What is a Karaite?
These were apostate Jews, coming to fruition in the 9th century CE (shortly before it died out) who denied the authenticity of the oral mitzvot (Talmud). The Karaites were a sect which appears to have begun when the Muslims defeated Jerusalem in the 7th century C.E, reaching its peak in the 9th century CE (900 years after Jesus), mostly dying out less than a hundred years later.
The Karaites rejected the oral mitzvot (Talmud) hundreds of years after the oral mitzvot had been recorded. There are people today who call themselves Karaites, but do not confuse the ancient group with people who today claim to be Karaites. There are less than 100,000 Karaites worldwide (about 30 - 50,000 in Israel), and most are not even Jewish. In 1932, according to the Jewish Encyclopedia, there were only some 10,000 of them in Russia and approximately 2,000 elsewhere in the world. The modern Karaites claim they are descended from the ancients, but this seems highly unlikely. Modern Karaism took the name of the ancient group -- and while they claim to be linked to them that link is precarious indeed. From Aish's Crash Course on Judaism regarding the Karaites.
(The Muslims defeated Jerusalem in the 7th century CE (Omar). This is where we begin the history of the Karaites). "Indeed, when Omar defeated the Persians and took over Babylonia, he immediately gave his blessing to the Reish Galusa to head the Jewish community. As a matter of fact, Omar was so fond of the Reish Galusa -- Bustenai Ben Haninai -- that when he himself decided to marry the daughter of the Persian king, he insisted that Bustenai marry her sister. Thus in a bizarre twist of fate, the Reish Galusa became brother-in-law to the caliph.
(After the death of Bustenai, his sons by an earlier wife sought to delegitimatize his sons by the Persian princess, claiming that she never converted to Judaism. However, this was unlikely as the case of a Reish Galusa marrying a non-Jewish woman without conversion would have caused a furor and public condemnation. Indeed the Gaonim of the day ruled that all his children were legitimate Jews.)
During the long history of Babylonian Jewry, sometimes the Reish Galusa wielded more power, sometimes the Gaonim. Much depended on the political climate and the personalities involved. Generally, however, the position of the Gaon was determined by scholarship, while the position of Reish Galusa was depended on lineage (as the Reish Galusa was traditionally the descendant of King David.)
And it was a dispute over lineage that gave rise to a splinter sect in 8th century Baghdad -- a splinter sect that came to be known as the Karaites.
When Shlomo, the Reish Galusa, died childless in 760, two of his nephews Hananiah and Anan vied for the position. Hananiah got the job and Anan went off to start his own religion.
This is another example of a pattern we have seen previously -- a split among the Jews due to an ego problem. (We saw it, for example, in Part 20 with Rehoboam and Jeroboam.)
The sect that Anan started in some ways was similar to the Sadducees. Like the Sadducees, the Karaites didn't recognize the authority of the Oral Torah and hence they read the Written Torah literally. (Their name, Karaites, comes from the Hebrew verb, kara, meaning "read.")
As we saw earlier, it is impossible to live a Jewish life without the Oral Torah as so much of the Written Torah is not specific enough. Thus, where the Torah commands "and you shall write them [these words] upon the doorposts of your home," how can anyone know which words of the Torah, or indeed, if the entire Torah is to be written on the doorpost? It is the Oral Torah that explains that this passage refers to the words of the Shema prayer, which are to be written on a parchment scroll and then affixed in a specified place and manner on the doorpost. The mezuzah!
As a result of their literal reading of the Torah, the Karaites came to observe Shabbat in total darkness, unable to leave their homes all day except to go to the synagogue. They did away with the observance of Chanukah because it is not mentioned in the Written Torah, as well as with the separation of meat and milk for the same reason.
One might think that this sect would have little appeal, and initially it did not. But, with time, the Karaites began to attract those Jews who wanted to dismiss the opinions of the rabbis; this turned out to be a huge draw.
That is, until the great sage, the Sa'adiah Gaon entered the picture.
Sa'adiah Gaon is famed for his writings, particularly the Book of Belief and Opinions, and for his critiques of the Karaites which made mincemeat of their beliefs.
His arguments stopped the spread of Karaitism which could have overwhelmed the entire Jewish world. It was so popular at one point that in the 10th century the majority of Jews in the Land of Israel were Karaites.
However, the Karaites never recovered from the assault of Sa'adiah Gaon on the logic of their beliefs. Their numbers shrunk with time, though unlike the Sadducees, they never completely disappeared.
(Incidentally, up until World War II, there was a large Karaite community in the Crimea, which in trying to save themselves from the Nazis, claimed that they were not actually Jews. Of course, they were murdered too.)
Today, there is a small number of Karaites left, living chiefly in Israel, though no one is sure how many as the Karaites forbid census-taking. Their population has been variously estimated at 7,000 all the way up to 40,000. The Karaites are reputed to be very religious people, and from the outside appear indistinguishable from Orthodox Jews, though they are forbidden to marry other Jews and marry only each other.
When the Sa'adiah Gaon died in 942, the period of the Gaonim of Babylon was almost over. It would officially end in 1038 with the death of Chai Gaon."
The Rambam opined that Karaites of 1000 years ago were not heretics (as many other Jewish sources opined), but were ignorant, acting in error based on the customs they were taught. They were not intentionally heretical, per the Rambam, but were like kidnapped children who don’t know any better.
Whether an apostate (heretic) or in error it is quite clear that referencing a Karaite is NOT appropriate or logical. This is not a "Jewish source" any more than quoting some non-normative Christian source would be acceptable as a "Christian source."
Yefet ben Ali, therefore is not a "rabbinical" source. He rejected rabbinical Judaism!
The Driver and Neubauer book mentions that Yefet ben Ali personally saw the passage as messianic he also states that many Karaites view the servant as the Jewish nation, and that Saadia Gaon (9th century CE) viewed the servant as Jeremiah the prophet. "Some of the learned (Karaites) apply the prophecy to the pious of their own sect (the Jewish people), resting their view upon two arguments: In the first place, because their history answers to the descriptions given in this section; and secondly, because of the word "lamo" (in their deaths), which is plural. Others of them think the subject of it to be David and the messiah, saying that all the expressions of contempt, such as "many were desolated at thee", refer to the seed of David who are in exile (the Jewish people); and all the glorious things, such as 'behold my servant will be prosperous' and 'so shall he sprinkle', refer to the Messiah." The 53rd Chapter of Isaiah According to Jewish Interpreters by Driver and Neubauer.
As anti traditional Judaism as he was, Yefet ben Ali was just as anti-Christianity -- another fact missionaries never mention to their followers as they quote him.