The following is from Chabad.org:

Long recognized as a one of the most brilliant minds of the past generations, but whose writings were primarily relegated to the purview of a small cadre of scholars, the Rogatchover Gaon – literally, the “genius of Rogatchov” – has for many years occupied a lofty space, inaccessible to the masses. A new volume released by the prestigious Jerusalem publishing house of Mosad Harav Kook seeks to change all that, providing the keys, so to speak, to unlock the teachings of the early-20th century rabbinic leader.

Written by Rabbi Avraham Benshimon, a scholar and educator in Montreal, Canada, the work thematically annotates and explains the writings of Rabbi Yosef Rosen, whom the Lubavitcher Rebbe, Rabbi Menachem M. Schneerson, of righteous memory, credited with “brilliantly shaping general rules for every single concept in Torah study.”

As a young child in Rogatchov, Belarus, Rosen earned a reputation as a brilliant and diligent scholar. He later became one of the two rabbis of Dvinsk.

“It was said of him,” writes Rabbi Shlomo Yosef Zevin, author of the Talmudic Encylopedia, “that he never took a haircut, because he never wanted his head to be uncovered and stop him from his studying.”

But while his in-depth analyses on Talmudic concepts have been discussed by various commentators, much of Rosen’s work has not been popularly studied. His writings frequently employ the use of short staccato sentences of enormous depth, alluding to an underlying logic, but demanding patient reflection on the part of the student.

“The Rogatchover wrote his commentary very [precisely], and without further explanation,” relates Rabbi Yosef Motchovitz of Mosad Harav Kook.

“When you begin to study the Rogatchover’s works, short in words, but long in the depth of what they explain, you find someone who has the authoritative power over all parts of scholarly Jewish teachings,” explains Zevin. “He finds what connects all of the aspects of the particular laws on a subject and then breaks it down into rules that explain difficult passages in those laws.”

On more than one occasion, the Rebbe pointed out that the Rogatchover’s genius stood unmatched. Beginning when he was 17, the Rebbe corresponded with Rosen, and would later base his teachings on some of Rogatchover’s foundations.

“He ate, drank and slept like every human being,” the Rebbe said in 1987, “however, his way of learning was wondrous.”

According to Motchovitz, Benshimon – who just completed his third volume on Rosen’s commentary to Maimonides’ legal code – has “brilliantly intertwined the words of the Rogatchover with his annotations and explanations.”

For Benshimon, dean of the post-yeshiva Kolel Ledayanus in Montreal’s Petach Tikvah Synagogue and an instructor at the Lubavitch Women’s Seminary, the new book represents a practically unending quest to research every one of the sources referenced by Rosen.

“When commentaries cite a source, they bring down a few words about what they’re referring to,” he explains. “But the Rogatchover never [spells out] what he’s referring to on the page, or sometimes in an entire chapter.”

Motchovitz says that the result is a brilliant and cohesive commentary.

“We were astounded the first time we reviewed the material,” he states. “Our editorial staff had to do very little touchups to the text.”

Benshimon, who studied in the Central Lubavitch Yeshiva in Brooklyn, N.Y., and the Chabad-Lubavitch run Rabbinical College of Canada, works directly from Rosen’s handwritten notes provided by Machon Tzofnas Paneach, the association formed to preserve his teachings.

Benshimon “is a great Torah scholar,” says Motchovitz, “and we are looking forward to publishing many more volumes.”

(Source: Chabad.org)