Tanya Chapter 23, Class 10 (180). PLEASE NOTE THAT THE MATERIAL IN THIS CLASS IS בדרך אפשר (THE OPINION OF THE TEACHER ALONE). In this class we return to the few lines on 29a, where the Alter Rebbe addresses the question of interrupting to learn Torah [not only to do Mitzvos, but] also to Daven [even though תורתו אומנתו פטור מתפילה] for one who is not Toraso Umnaso (he uses time for things other than Torah study) and מאחר דמפסיק ומבטל בלאו הכי [since he wastes time anyway]. Now, why would wasting some time justify wasting more of it? Answer (בדרך אפשר): because he is missing the qualitative level of Toraso Umnaso, so he MUST Daven to protect his Torah from being wrong (סם המות).
