Thus, too, the menorah is an emblem of the whole of the souls of Israel.
And, according to the Torah, it is all beauty, entirely of gold.
As the phrase in the Song of Songs puts it, “Thou art all fair, my love.”
The original menorah was cast in one piece of gold; the menoras in following generations were mixed with other ingredients, made of alloys, and pieces of different metals that were joined together.
Even a stone menorah is incomplete in that it has to be carved, fragments must be cast off.
It is not of one piece.
The idea is that Israel has to be a wholeness; each member is responsible and liable for the others in a singleness of essence.
–Rabbi Adin Steinsaltz