Lech Lecha: How Avrohom Transformed Divine Promises Into Guarantees Through Ma'aseh Avos

The shiur opens with a fundamental principle: the Torah (תורה) is not a biography of great individuals but the covenant document of the Jewish people. Its purpose is to record how Am Hashem (ה׳) was created, not to chronicle the righteousness of the Avos. This explains why towering figures like Avrohom and Yitzchok "vanish" from the Torah narrative for decades at a time. Avrohom disappears after the Akeidah (age 137) for his final 38 years; Yitzchok vanishes after blessing Yaakov (age 123) for his remaining 57 years. The Torah records only those episodes that actively formed the character and destiny of Klal Yisrael. Rabbi Zweig demonstrates this principle through the concept of "passing the mantle." Once Yitzchok established Tefillas Mincha at age 40, Avrohom became obligated to daven Mincha—showing that Yitzchok had become the Av, the father-figure actively shaping the nation. Tosafos (תוספות) notes that although the Gemara (גמרא) in Yoma attributes Mincha to Yitzchok, it is also called "selusa d'Avrohom" because Avrohom adopted it after Yitzchok instituted it. Similarly, when Yaakov established Maariv upon leaving Yitzchok's home, the mantle passed again, and Yitzchok's active role ended.