Dan,

I've translated the Grossman source provided by Rossi and it says:

"According to many researchers, Rashi was also included in this family [refers to the tree printed on page 91], because she [Rashi's mother] was a sister of Rabbi Shimon ben Yitzchak [according to these scholars]. This is based on the words of Rashi himself, who mentions in his commentaries several times the Torah words of a sage named R. Shimon the Elder, whom he calls "my uncle" or "my mother's brother", who received Torah from Morgam'a [i.e. R' Gershom]. Mikal and Zunz [two scholars] assumed that he was Shimon ben Yitzchak. Others received from them, and there are also [who] from the latter, still hold this belief. Weiss [another scholar] came out against this identification, in his response, because we did not find that Rabbi Shimon ben Yitzchak was called "the old man," but "the great one," and that he was not a student of Ragam'a [R' Gershom]. It is difficult to rely on the first argument. It is doubtful whether there is any consistency in giving titles of this kind, especially when the title "the great" originates (in homage to Rabbi Shimon) in the Beit Madrasham of Sidi Ashkenaz, the later Rashi [not sure of the translation of this last phrase]. His second claim is true, and it can be helped from another source, from the chronology. R. Shimon ben Yitzchak was older than Margam'a Katz [i.e. R' Gershom], according to Rashi's words, "It is seen in the eyes of Rabbi Shimon bar Yitzchak and in the eyes of Rabbi Gershon N'A and in my eyes Solomon of Troyish, the city in France." [The author here implies that the order of the Rashi's list shows the respective ages of the Rabbis as explained in the next sentence] Rashi highly valued Ragma [R' Gershom] and saw him as "the greatest of the world". It is far from him, therefore, that he would have [named] Rabbi Shimon ahead of him, if he had not been the older of the two. Also in the legendary source mentioned above there is a hint of this, "And when Rabbi Gershom came to our Rabbi Shimon the Great, they received a beautiful welcome and read the Torah together." Rabbi Shimon's estimated time is 950-1020, and it is even possible, if not slightly earlier. It is difficult to interpret, because his sister gave birth to a son in 1040, which is the year of Rashi's birth. [This last sentence is difficult for me to translate but I believe what Grossman means is what you were saying in the initial post: it would be difficult chronologically for R' Shimon the Great, 950-1020, to have had a sister who gave birth to a son, Rashi, in 1040].

All bracketed material is my commentary.



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Adam Cherson,NY, NY
Benyakonski, Kherszon, Rubinovich, Solts, Grodsinski, Levine, Cohen, Kaplan, Lubetski, Karchmer, Horwitz, Rabinovich, Zussman (Lida, Voronova, Dieveniskes, Konvaliski, Smarhon, Vilna)
Genomics Publications and Presentations: https://independent.academia.edu/AdamCherson