Jewishness is determined by matrilineal descent, so those of the lost tribes would have to convert.
But is not tribe determined by patrilineal descent? Being an Israelite means being a “son of Israel”, no?
So, after conversion, what is their status? And assume their tribe is known (somehow).
Unfortunately, we do not need to speculate widely about the application, as this type of scenario does occur in our day.
R. Dov Lior addressed the following question (דיני גר בן לוי):
האם אדם שנולד לאם גויה ולאב יהודי (לוי) והתגייר עם אמו כשהיה תינוק יחשב לוי לענין העליה לתורה (ובכלל לענין העבודה בבית המקדש..)?
לא, במקרה כזה, דהיינו: נישואים בין יהודי לשאינה יהודיה, הולד הולך אחריה. והיות והוא התגייר, מבחינה הלכתית האבא לא נחשב אביו ואין לא יחוס והוא לא יחשב כלוי.
Question: If a person born to a gentile mother and a Jewish-Levite father converts with his mother when he was a child, is he considered to be a Levite for the purpose of getting called up to the Torah, or for the service of the future Temple?
Answer: No, in a situation such as this, involving the marriage between a Jew and a non-Jewess, the child goes after her. And since he converted, from a halakhic point of view the father is not considered to be his father and there is no lineage connecting them and he will not be considered a Levite.
Conversion severs the halakhic identity ties between a convert and his biological parents. The same answer applies, whether we know the individual patrilinealy descends from any of the other tribes as well.
The Gemara in Yevamot 17a states that the 10 lost tribes have the status of non Jews and therefore must convert
The notion that converts to Judaism are descendants of the lost tribes of Israel is a debatable topic in the Jewish tradition. Some sources support this idea, while others reject it or suggest alternative interpretations. Nevertheless, after analyzing various texts from Jewish tradition, it is plausible to argue that converts are indeed descendants of the lost tribes of Israel.
One source that supports this idea is the Midrash (Bamidbar Rabbah 2:9), which compares converts to a lost object that has been found. This metaphor suggests that the convert was once part of the Jewish people but became separated or lost and has now returned. The Zohar, a mystical text in Jewish tradition, refers to converts as "the sparks of Israel that have been scattered among the nations" (Zohar Chadash, Shemot 22b). This suggests that converts are seen as part of the Jewish people who were lost or scattered but have now returned.
The Yalkut Shimoni, a collection of midrashic teachings, states that "the converts are the remnant of the lost tribes" (Yalkut Shimoni, Isaiah 60:1). This suggests that converts are seen as the remnants or descendants of the lost tribes of Israel who have returned to the Jewish people through conversion. The Midrash Shocher Tov teaches that "the converts are the lost tribes of Israel" (Midrash Shocher Tov, Psalm 147). This view suggests that converts are not only descendants of the lost tribes but are, in fact, considered to be the lost tribes themselves who have returned to the Jewish people through conversion.
The Targum Yonatan is an Aramaic translation and commentary on the Torah. In Targum Yonatan, it is written that "the converts are the remnant of the lost tribes who have returned to the God of Israel" (Targum Yonatan, Exodus 12:49). This text suggests that converts are seen as the remnant or residue of the lost tribes who have returned to the God of Israel through conversion.
The 19th-century rabbi and scholar Samson Raphael Hirsch wrote that "every convert is a representative of his tribe, and by his conversion, the tribe is redeemed" (Horeb, Section 301). This view suggests that when a member of a lost tribe converts to Judaism, it is a sign of the tribe's redemption and return to the Jewish people.
In his essay Ma'amar Chikur Din, the 17th-century rabbi and scholar Menachem Azariah of Fano discusses the concept of conversion to Judaism and its relation to the lost tribes of Israel. He writes that "the converts are the lost tribes who have returned," suggesting that converts are not only members of the Jewish people but are specifically descendants of the lost tribes who have returned through conversion.
This view is significant because it emphasizes the idea that converts are not outsiders or newcomers to the Jewish people but are, in fact, part of the larger Jewish community and connected to the history and destiny of the Jewish people. It also suggests that the return of the lost tribes is not solely a physical or political event but can also occur through spiritual means such as conversion.
The 13th-century Spanish rabbi and scholar Nachmanides wrote that "the convert is like a lost member of the house of Israel who has returned to his people" (Commentary on Leviticus 19:33). This suggests that converts are seen as lost members of the Jewish people who have returned through conversion.
When taken together, these texts provide a strong case for the idea that converts to Judaism are descendants of the lost tribes of Israel. The Midrash (Bamidbar Rabbah 2:9) compares converts to a lost object that has been found, suggesting that they were once part of the Jewish people and have now returned. The Zohar refers to converts as the "sparks of Israel that have been scattered among the nations," suggesting that they are part of the Jewish people who have been lost or scattered. The Yalkut Shimoni, Midrash Shocher Tov, and Targum Yonatan all suggest that converts are seen as remnants or representatives of the lost tribes who have returned to the Jewish people through conversion.
The topic of the status of converts within the Jewish community has been the subject of debate for centuries. While some sources suggest that converts are fully integrated members of the Jewish nation, others indicate that they may also be part of the lost tribes of Israel. This idea holds much significance for the coming of the Messiah. One such source is the Talmud (Sanhedrin 94a), which describes a future scenario in which the ten lost tribes of Israel will be reunited with the rest of the Jewish people. According to this passage, the lost tribes will be identified by their observance of the mitzvot.
The son of a Jewish father and a non-Jewish mother, is technically not the father’s son. Legally, spiritually, and Kabbalistically, a Jew cannot be related to a non-Jew. Therefore, the non-Jewish offspring of a Jewish father and a non-Jewish mother, does not have any Jewish heritage whatsoever. This heritage includes the father’s Jewish tribe. The non-Jewish son, therefore, does not inherit any sort of tribe from the father. Once he converts, he doesn’t become related to the father. The father is as if a complete stranger to him.
All converts to Judaism count themselves as a generic "Yisrael", but without specific tribal affiliation. Their children, born from a Jewish woman, are also "Jewish", but also have no particular Tribal affiliation.
Jewish "Tribal" affiliation is determined by patrilineal lineage from each of Jacob’s twelve sons, provided the child was born from a Jewish woman.
If a child was born from a non-Jewish woman, that child is cast after its non-Jewish woman, and is considered a non-Jew, and tribal affiliation is not passed to that child; despite having a biological father who is a Jew.
Therefore, even if a person is an alleged member of the "lost tribes", but was born from a non-Jewish mother, then his relation to those "lost tribes", is meaningless. They are not Jewish, and have no obligation to convert to Judaism, just the same as any other gentile has no obligation to convert to Judasim.
If they decide to convert, they have the same status as any other convert. They are a generic "Yisrael".
I would like to provide additional information to answer this question, as other individuals have shared further perspectives. Thank you for taking the time to consider my input.
The Midrash From Psalm 147: "Another interpretation of "נדחי ישראל יכנס" [Rejected Israel will enter] is referring to the tribes, as it says in Deuteronomy 29:27 "He has cast them into another land." Similarly, the verse in Isaiah 27:13 says "and those who were lost will come." At that moment, Israel has no pain until they are healed, as it says, "The doctor for broken hearts."
The return of individuals is deeply meaningful both to Hashem and to those whose "broken hearts" are healed through this process. From the writings of the Prophets, we know in Jewish eschatology, reuniting the lost tribes is seen as a crucial step before the arrival of the Messiah.
Further, the Midrash Rabbah Kohelet Parashah 1:18 states "R'Yochanan said: Not only that, but in the place where he converts, from there he will receive his portion, as it is stated, It shall be that the tribe within the proselyte is converted, there shall you allot his inheritance (referring to Ezekiel 47:38)."
The commentary of this verse from the Radal goes on to elucidate, "our verse is saying not only those who converted in the world will be togther with the rest of the nation in the Future, when Israel's status will be elevated, but it is saying that they will receive a portion (an inheritance in the land) in the very place where they flowed".
To summarize, it is important to recognize that even those who are not born Jewish might still hold a significant tribal identity. The act of returning to the lost tribes, even if it is through conversion, holds deep meaning and offers hope for redemption and the restoration of Israel's identity as a whole.
A Jewish convert is considered an Israelite.
I can’t find the specific source, but when Meshiach comes, Eliyahu ”will inform every Jew to which of the twelve tribes he belongs. (His ability to establish the tribal ancestry of every Jew stems from one of his favorite pastimes—attending circumcisions. Who better to recount the lineage of every Jew than someone who was at every Jewish circumcision?)” chabad
The lost tribes, once identified by Eliyahu, would not need to convert since they have Eliyahu as the witness of their Jewishness.
