Chassidic work containing the writings and lectures of R' Kalonymus Kalman Epstein, collected and published by his son, R' Aharon under his father's direction. It was printed in some editions of Mikraot Gedolot alongside the standard commentaries and is considered a prime text in Chassidic literature, to the point that it was coined by some as the 'Shulchan Arukh of Chassidut'.