By adding the letter ה' to the name אברם it becomes אברהם. The letter stands for the word “המון-multitude,” referring to how Avram is now able to elevate a multitude of sparks of holiness that are trapped in this world, in a way he was never before able to. This process of descent from his level of Lofty Wisdom until Malchus was accomplished through the mitzvah of Milah.
Chapter 2
Now, according to this, it is only a descent to go from אבַׁרם-Av Ram to אברהם-Avraham. Based on what was said so far, the letter ה' added to אברם corresponds to “המון-multitude,” i.e., Avraham’s ability to elevate the world around him. Seemingly, the Lofty Wisdom of Avram doesn’t “gain” anything by descending to Malchus, it descends only because of Hashem’s command. However, the Alter Rebbe will now clarify that Avraham himself actually reached a higher level through this process. This is because the ability to descend comes from a very lofty level called Keser-Crown or Atik-Removed and Transcendant, which is even higher than the Lofty Wisdom of אב רם. This higher level becomes manifest in the letter ה' of Binah-Understanding. In this new explanation, the added letter ה' in אברהם corresponds to Bina, which receives from Keser, which enables the Lofty Wisdom to descend into Malchus.
