R. SHMUEL SOFER
R. Shmuel Rabinovitch (d. 5675), known as R. Shmuel Sofer or R. Shmuel der Shreiber, lived in Lubavitch where he made a living as a copyist of maamorim, like his father, R. Meir, before him. During this period, the Rebbeim's maamorim were not published, instead circulating among the chassidim in handwritten copies. R. Shmuel was the considered the premier copyist due to his precision and neat script, and the Rebbeim commissioned his work constantly. Until recently, many of the maamorim of the Rebbe Maharash were only available in photocopies of R. Shmuel's handwriting.
Having just spent Shabbos by the Tzemach Tzedek, the chossid R. Leib Moninsohn, asked the Rebbe if he could get a copy of the maamar right away, as he was pressed to leave town the next day. The Rebbe agreed and told him to call R. Meir der Shreiber. When R. Meir arrived, the Rebbe showed him where to sit and what to copy from a manuscript.
Meanwhile, the Rebbe sat at another table in the same room and began learning Gemara aloud, with a tune. After learning the sugya according to Rashi's commentary, exclaiming "dus iz noch Rashi," he proceeded to learn it according to Tosefos. Then he learned it according to the Rosh and then the Rif and Ran, each time noting which commentary it was. Finally, the Rebbe enumerated all the halachos deduced from the sugya, and the Gemara's meaning according to Kaballah.
As he ran out of space on the table, the Rebbe spread out more seforim on a surface on the ground. With a candle in his hand, he walked around looking through them, clarifying the various opinions and halachos. Upon clarifying the entire sugya, the Rebbe started singing the Alter Rebbe's niggun and began dancing.
The entire time, R. Meir sat there in awe watching the Tzemach Tzedek. When the Rebbe finished his dance, he approached R. Meir to see how much he's done and discovered that he only wrote a few lines. "Petach, fool!" said the Rebbe, "you can go home."
When R. Meir shared with the Tzemach Tzedek's sons what he had seen, they weren't amazed. "Our father does that every night," they told him.
(רשימות דברים חדש ע' 123)