On the wedding day of the Alter Rebbe’s grandson, Rabbi Nachum, the Rebbe asked the groom for permission to alter his silk coat so that it would require a patch.
The young groom refused his grandfather’s request. The Alter Rebbe then offered to learn Torah privately with his grandson if he agreed. Rabbi Nochum refused again. Finally, the Alter Rebbe offered the young man a place with him in Paradise! Rabbi Nochum replied, “Do I have to want it or can I just accept as an act of self-nullification.” The Alter Rebbe answered, “You must truthfully want it to the core of your soul.” Hearing this Rabbi Nochum remained silent.
Later, the chasan allowed his grandfather to remove a piece from the bottom of the coat’s long fur collar and received a blessing for long life.
Our Rebbe comments on this story, pointing out how amazing and surprising it is. We are talking about Rabbi Nochum, the son of the Mittler Rebbe, the Alter Rebbe’s grandson. Even though he was very young, he had been raised and educated in the precincts of the Alter Rebbe. And the fact that the Alter Rebbe invited his grandson to be with him in Gan Eden shows the greatness of Rabbi Nachum. That being the case, how could his clothing be so important to him that the Alter Rebbe had to offer part of his own share in paradise to induce Reb Nochum to modify it?
Furthermore, for the Alter Rebbe, who was a holy Talmud chacham, to make such a promise is astonishing because every Yid has free choice! Nevertheless, the Alter Rebbe took the responsibility to offer his grandson a place with him in Gan Eden!
We can explain this by pointing out that in every generation and in every location, there are areas of unholiness which are overwhelmingly strong. For example, the Gemara reports that King Menasha told a holy amora, in a dream, that had the amora lived in Menashe’s generation, he would have lifted his robe and run to serve idols.
Similarly, in the time of the Alter Rebbe there was a very strong slavery to fashion. To break this klipa, the Alter Rebbe felt compelled act and was even willing to give up a share in Paradise. Had the Alter Rebbe succeeded with his grandson, it would have positively influenced the rest of his family [and the rest of the generation] for years to come. [Yud Tes Kislev 5723]