Pulling the Strands Together
Haas makes no attempt to identify this S. who was responsible for these commentaries, and possibly for certain innovations in Jewish biblical exegesis. It occurred to me, and obviously I have no basis for saying this, that it could be cool if the mysterious S were R. Shemaiah, a key figure in Rashi's inner circle, whose independent exegesis is only slowly being uncovered (mostly by Avraham Grossman in his Hakhmei Tsarefat ha-Rishonim).
2. Amos Geulah, Lost Aggadic works known only from Ashkenaz : Midrash Abkir, Midrash Esfa and Devarim Zuta, Ph.D. dissertation, Hebrew University 2006
I've been waiting to see this dissertation, written under the supervision of Avigdor Shinan. I finally got my chance last week, and it is quite impressive. Geulah traces these three midrashim, known principally from short citations in Ashkenazic works such as Yalkut Shimoni, back to southern Italy in the 10th century. He then posits, based on when the citations start appearing in Ashkenaz, that there were several waves of immigration from southern Italy to Ashkenaz, each of which brought new books into the Ashkenazic "bloodstream". That is a suggestive idea, and makes more sense than trying to pin everything on those few immigrants known by name - R. Meshulam ben Kalonymus of Lucca, R. Kalonymus of Rome and R. Shmuel ben Natronai of Bari.
One of the most elegant parts of his work is where Geulah endeavours to show the connection between the three midrashim he studied and several other works that probably emanate from the same time and place - notably, Sefer Yerushalmi (the emended Jerusalem Talmud quoted by R. Eliezer ben Joel of Bonn) and the later additions to Midrash Tehillim. He managed to find a single example that pulls them all together.
One of the citations from Midrash Avkir makes reference to the custom of throwing tzitzit strings (over the shoulder) and behind one's back. Like the way some people wear a scarf. This same image, and the midrash based upon it, is found in the Ashkenazic manuscripts of Midrash Tehillim and in a citation from the Yerushalmi in various sources (including the Auerbach edition of Sefer ha-Eshkol!), but not in any extant version of the Talmud Yerushalmi itself. Geulah traced this custom through other sources, including a 14th century Ashkenazic manuscript with a picture illustrating this practice.
The lines between Ashkenaz and Italy become a little blurred in this discussion. But it is fascinating how Southern Italy has become the favourite destination for Hebrew compositions seeking a home. A few years ago, Ezra Kahalani suggested it as the origin of Aggadat Bereshit. If I remember correctly, Marc Bregman said that Tanhuma Buber was from northern Italy. Ta Shma thought that Sefer ha-Ma'asim was written in southern Italy, or elsewhere in Byzantium. What's cool about Geulah's work is that he actually found a criterion for placing these works together.
To tie these two discussions together, Grossman suggested that R. Shemaiah was himself from Byzantium, or that he had ties with the area.