Chayey Sara Patriarchs (12) Likutei Sichos – Vol 15 p 145 ff After Sara passes away we see her live. Her life is about the Jewish people exclusively while Avrohom is about all of humanity. This shows itself in each of the big events in this Parsha.

Vayera Patriarchs (07) Likutei Sichos Vol 25 p 86 ff Yitzchok’s Bris is superior not only to Yishmael’s but to Avrohom’s as well. Though Avrohom’s Bris was from higher than reason, but his 99 years of preparation cover this over and the idea that it is entirely from Hashem is not obvious.