“I will make you into a great nation.”
Previously we discussed how Abraham was able to create joy in the Universe, and how his name hints at the union of the spiritual Cosmic Man (Zeir Anpin), and Cosmic Woman, which he helped achieve.
With the giving of the Torah, the opportunities for such unions became more readily available. They are achieved, in different fashion, on New Moon, Rosh HaShana, and on Three Holidays. Abraham was able to achieve this in his days, but since his own main characteristic was kindness, it followed that he supplied mostly Kindness to the union, and the Cosmic Man, who benefited from it, grew mostly in his Wisdom, which is connected to Kindness. That is what God told Abraham, “I will make you into a great nation,” emphasizing “you” personally, with your unique qualities.
Isaac, too, was able to achieve this union, and his contribution came from Strength, which was his main part, resulting in the Cosmic Man's growing in Understanding, which is connected to Strength. However, something new happened in the days of Jacob. His quality was that of Balance, which is alternatively called Beauty, Truth, and Completeness. His bed and progeny was complete (twelve tribes), and he was able to reconcile Kindness with Strength. For the Cosmic Man it meant that Knowledge was added to his brain. The balance was greater than the some of its part, because now a complete whole could emerge.
Nevertheless, it was Abraham, who received an extra letter “hey” in his name, and his “hey” hints at Understanding, “Binah,” which is mostly responsible for the Cosmic Man's maturity. Its lower-level manifestation starts in Victory, Glory, and Foundation, which in a human body correspond to the right leg, the left leg, and reproductive organs, and from there the Understanding proceeds to the brain. That is why, after Abraham merited to arouse the Upper Union, he was given the letter “hey” in his name. In truth, Isaac and Jacob did not heed an extra letter manifestly, because they already received this influence from Abraham.
Art: Frederic Bazille - Family Reunion