The Rebbe reveals:
– Avraham was already 75 years old when he received the command “Go out from your land, your birthplace, and your father’s house.” (“Breishit”, 12:1).
He had already carried out several elevated services to G‑d — he “recognized his Creator,” spread the awareness of Him throughout the world, and was willing to sacrifice his life for haShem. Nevertheless, none of these activities are explicitly mentioned in the Torah, for they represent his limited human efforts to live in a spiritual manner. [Thus they were unable to bring G‑dliness into the physical nature of the world.]
With the command, “Go out,” Avraham departed from this limited framework of reference. He began the service of nullifying the limitations that separate the spiritual from the material.
The word “Lech” also means “proceed,” and indeed, Avraham’s journey represented true progress, where every new step represents a ‘height’ incomparable to his previous position. He did not remain content with his previous service and sought to transcend his previous level entirely and proceed to a new and unbounded rung of service.
This process of advancement is reflected in the changing of his name from Avram to Avraham. Rashi explains that Avram has the implication “father of Aram,” while Avraham alludes to the Hebrew words meaning “father of many nations,” as now he was given the potential to elevate the entire world.
Based on the Rebbe’s talk on Shabbos Parshas Lech Lecha, 11th Day of MarCheshvan, 5752.