This Shabbat (3 Tammuz) coincides with the 18th yahrzeit of the Lubavitcher Rebbe, a profound student and teacher of Kabbalah, in additional to his many better known accomplishments.
A variety of teachings by him, from him and about him can be found in articles 1, 3 and 7 (and perhaps allusions to him in one or two of the others as well).