Why does the Torah write that "HaSh-m ascended from upon Avraham," rather than simply that "He departed from Avraham"?
Rashi #1: This is a more respectful way of speaking about HaSh-m. 1
Rashi #2 (based on Bereishis Rabah 47:6): This teaches that the righteous are the "chariot" (Merkavah) of HaSh-m. 2
Seforno: Aside from the precise wording, he explains that, as opposed to the Pasuk in Bereishis 4:15, which states that "Kayin left the presence of HaSh-m," here it was HaSh-m Who ascended from Avraham. This demonstrates HaSh-m's love for Avraham.
Gur Aryeh: In what way does the Torah alter its wording? The Shechinah was next to Avraham, and the Torah changes this and writes "upon" Avraham, meaning above.
QUESTIONS ON RASHI
Rashi writes: "We learn that the righteous are the 'Chariot' (Merkavah) of HaSh-m." Ramban asks - the Midrash (Bereishis Rabah 47:6) says only that specifically the Avos are the Merkavah?
Gur Aryeh #1: Rashi understands that the three Avos represent a complete Merkavah, 1 whereas other individual Tzadikim are merely parts of a Merkavah, but not a whole one.
Gur Aryeh #2: Gur Aryeh himself prefers the text of the Midrash; only the Avos can be called a "Merkavah." This refers not only to the three Avos as a group, but each one of the Avos strove to excel at a particular Midah 2 (trait) of HaSh-m, and was a "whole" prototype for all those righteous people who would follow. 3
Ramban connects this to the Pasuk in Michah 7:20, which refers to "Emes l'Yaakov" and "Chesed l'Avraham." Chesed was the trait of Avraham, Pachad / Gevurah (fear) of Yitzchak, and Emes / Tif'eres (truth) of Yaakov, though Ramban intimates that this is a Kabalistic explanation that is beyond the ordinary person's comprehension.
Michtav me'Eliyahu (Vol. 2, Lech Lecha, p. 160): The Avos cleaved to HaSh-m with their entire hearts, even when they seemed to be tending to their mundane affairs. In turn, HaSh-m called His name upon them, and they were the Merkavah to the Shechinah. Avraham "carried" the trait of Chesed - bestowing upon others. Yitzchak "carried" Gevurah - self-introspection, and self-negation stemming from fear of Heaven. Yaakov "carried" Emes - not veering either to excessive Chesed or to excessive Gevurah. Each of the three Avos used his trait to achieve perfection in all traits. (EK)