This class has three separate audio files. a. Introduction, b. Essay, c. Notes. 2. Kunteres Acharon 4. Lehavin Ma Shekasuv biPri Etz Chayim. Introduction. Essay. Notes. This essay may be the most difficult section in all of the Tanya. Its form is very mystical. It addresses first of all the effects of prayer. Then begins a deep discussion about the performing of physical Mitzvos and studying the aspects of Torah that relate to the performance of those Mitzvos. The class is divided into three: First a background on the mystical information discussed in this letter. Second the bulk of the essay itself. Third notes of the Alter Rebbe himself that constitute the latter portion of this essay.