I Will Write It In Their Hearts - Volume 4

In the Rebbe's correspondence one can see his scholarship, the care he has for every individual, the communal projects which he pioneered, and many other dimensions of his leadership.

Letter No. 481:
Lag BaOmer contains two elements: the ultimate ascent experienced by Rabbi Shimon bar Yochai, [as manifest in] pnimiyus haTorah, that was revealed on this day, and [the lowest levels of] acknowledgment, which is the divine service of utterly simple people, as explained in the kuntreis [published] in connection with the Pesach holiday.
Letter No. 483:
Letter No. 513: