Letters 21-24. Letter 21 deals with ZERIZUS (alacrity) in Yiddishkeit (which we can learn from Avrohom Avinu), and its lesson in giving Tzedaka often (even if in smaller increments). Letter 22a deals with the idea that only an actual Navi can help people with their material needs, while a Chochom (Rabbi) can only help them with matters of the spirit. The point was that people shouldn’t come to the Alter Rebbe with these kinds of issues. The Rebbe points out that the fact that the Alter Rebbe would answer such questions is proof that the Alter Rebbe had the category of one who can help even about physical matters. Letter 22b deals with sincerity in Davening and Ahavas Yisroel. Letter 23 deals with not talking in Shul not only during Davening but all the time. as ten Yidden invite the Shechina to be amongst them. Letter 24 deals with how painful and foolish it is to talk DURING Davening.
