Shiurim in this topic
מגן אבות (Magen Avos) is a work of Chassidic discourses (maamarim) on the Torah portions and festivals by Rabbi Shlomo Zalman Schneersohn of Kapust (d. 27 Iyar 5660 / 1900), son of the Maharil of Kapust, Rabbi Yehudah Leib, and grandson of the Tzemach Tzedek. He led the Kapust branch of Chabad after his father's passing.
The Rebbe's letters tagged here explain passages in Magen Avos, for example its statement that "Ashrei" is the opposite of "Hoi", and its discourse on the mezuzah being placed on the right.
Not to be confused with the blessing Magen Avos recited by the chazzan on Friday night.