Lech Lecha Likutei Sichos vol. 15 page 70 ff.Ten generations end and in one case they are destroyed and in the other they are uplifted.What is the explanation?

Lech Lecha Patriarchs (06) Vol. 01 page 18 ff. Yishmael’s Bris was rational, and that is a liability compared with Yitzchok’s super-rational bond. It is the basis of the Jewish people and that they are a miraculous people attached to Hashem higher than reason, from infancy.