"And G‑d appeared to him in Alonei Mamre, and he was sitting at the entrance of the tent during the heat of the day. [Abraham ] lifted his eyes and saw three strangers standing a short distance from him. When he saw [them] from the entrance of his tent, he ran to greet them, bowing down to the ground. He said, 'Sir, if you would, do not go on without stopping by me. Let some water be brought, and wash your feet. Rest under the tree. I will get a morsel of bread for you to refresh yourselves. Then you can continue on your way. After all, you are passing by my home"." (Gen. 18:1-5) All those who know how to unite His name in holiness can break down the barriers of darkness…
The Holy Zohar (parashat Vayera 98a) voices a famous question: The Torah says that G‑d appeared to him, but it doesn't say to whom he appeared. Although it seems obvious that G‑d appeared to Abraham, it doesn't say so. Why not?
In truth, G‑d appeared not only to Abraham but to every member of his household. And really, due to the brilliance of the light of Abraham and his great merit, all the people of the world benefited from the newly revealed light of G‑d. "And G‑d appeared to him…" means that He appeared to each and every individual - all in the merit of Abraham.
The Midrash says that the verse, "And G‑d said, Let there be light" (Gen. 1:3) refers to Abraham. The face of the King is hidden behind the valley of darkness as it is written, "And he makes darkness His hiding place…" (Psalms 18:12). All those who know how to unite His name in holiness can break down the barriers of darkness and cause the face of the King to be revealed; radiating light unto all. (Zohar parashat Beshalach 57a) Abraham bequeathed to every Jew the ability to radiate G‑d's light.
[First published in B'Ohel Hatzadikim, Vayera 5762]