A decade after their first meeting, the correspondence between R. Yosef Yitzchak and R. Menachem Mendel reveals the extent to which their relationship had developed. R. Yosef Yitzchak took great pride in his son-in-law’s command of Torah literature and frequently wrote to him, asking for critical feedback on his talks and writings. R. Menachem Mendel saw in his father-in-law the living embodiment of the chassidic spirit, and was enormously impressed by his psychological depth, strength of character and self-sacrifice.1

One letter addressed by R. Yosef Yitzchak to R. Menachem Mendel in 1933, elaborating on a teaching heard from his father, the Rebbe Rashab, exemplifies the type of instruction that R. Menachem Mendel sought and obtained from him:

My father explained to me the difference between Torah learning in which the student studies the Torah, and Torah learning in which the Torah teaches him... This explanation literally opened my eyes; especially the lessons he drew from living examples - the qualitative difference between people, all distinguished and all scholars… but these study the Torah and these the Torah teaches.2

There is a deep distinction between textual or theoretical knowledge and the type of lived wisdom that utterly transforms and refines the character of an individual.Their mutual desire to perpetuate this repository of lived wisdom... resulted in the development of a new literary genre. From his earliest youth, R. Yosef Yitzchak was impressed by people who taught through stories told of the exemplary individuals they had known, and who enlightened by their own example. Throughout his life he carefully curated such stories and transcribed them, along with his own memories of his father and chassidim of stature who exerted a seminal influence on the development of his own character and outlook.3

R. Yosef Yitzchak and R. Menachem Mendel’s mutual desire to perpetuate this repository of lived wisdom, stories and experiences, resulted in the development of a new literary genre. Previously transmitted orally, such accounts would now be transcribed for publication.

This collaboration began in earnest in 1934. After settling in Paris in the spring of 1933, R. Menachem Mendel and his wife remained there for a year without interruption. As stateless refugees, it was difficult for them to travel between countries. R. Yosef Yitzchak’s endeavors to make arrangements to reunite the family finally bore fruit in the summer of 1934, when R. Menachem Mendel traveled to meet him in Marienbad.4

Over the next twelve months R. Menachem Mendel hardly left his father-in-law’s side. The festival period of Tishrei was spent in Warsaw, where R. Yosef Yitzchak had moved to live in the vicinity of the Yeshiva. On doctor's orders to refrain from excessive talking and strenuous activity, R. Yosef Yitzchak spent the winter in the company of his son-in-law at the Westend Sanatorium in Purkersdorf, near Vienna. This was not the first time R. Menachem Mendel was on hand to assist his father-in-law with his medical needs; on an earlier occasion, R. Yosef Yitzchak expressed his gratitude in a letter to Chaya Mushka, “Your husband… is attentive to everything I need… not simply as a dedicated son-in-law, but like a good daughter.”5

During this time R. Menachem Mendel made several long entries in his personal journals, recording hundreds of stories and historical vignettes related to him by R. Yosef Yitzchak. He also meticulously noted the manner in which R. Yosef Yitzchak observed mitzvot and seasonal customs.“Your husband… is attentive to everything I need… not simply as a dedicated son-in-law, but like a good daughter.”6 R. Yosef Yitzchak himself was a prolific writer, and this was one area where the doctors did not restrict his activity. The letters he wrote over the course of this winter are particularly expansive, rich with chassidic tales and personal memories alongside explanations of their ethical implications.7 R. Menachem Mendel explicitly cites some of these letters in his journals, and the longest of them - covering more than 130 pages in print - was addressed by R. Yosef Yitzchak to his daughter, R. Menachem Mendel’s wife, Chaya Mushka.8

The previous summer, an idea for a journal devoted in part to Chabad history, thought and ethos, and in part to general Talmudic and halachic issues, was encouraged by R. Yosef Yitzchak.9 But it seems that these intentions did not materialize until R. Menachem Mendel became involved. In the spring of 1935 R. Yosef Yitzchak informed his daughter of her husband’s activity, “through the work and dedication of your honored husband, my precious and beloved son-in-law… an important journal will soon be published, titled ‘Ha-tamim.’ On paper the editors will be others, but all the work is his.”10

“Ha-tamim” made Chabad teachings and traditions more accessible to a wider audience. But its most lastingly significant feature showcased R. Yosef Yitzchak’s own letters and memoirs. Uprooted from its native Russian ground, and resettled in Poland, Chabad was in danger of losing its identity. The oral histories transcribed and preserved in the pages of “Ha-tamim” served to vividly illustrate and successfully preserve the spiritual and ethical contours that make Chabad unique.

As Rebbe, R. Menachem Mendel would cite many anecdotes transmitted by R. Yosef Yitzchak as the basis for his own teachings. Even more striking was R. Menachem Mendel’s application of analytical methodologies normally reserved for Talmud study as a tool to further amplify and develop the ethical and religious import of the living spirit of R. Yosef Yitzchak’s literary oeuvre.11