Binah, understanding or discernment, is the third Sefirah and the head of the left column. If Chokhmah is the point, Binah is the palace: it takes the flash of the idea and unfolds it in length and breadth, in details, into a world. The word comes from the root "between": to understand is to distinguish one thing from another. Elijah places it in the body: "Binah is the heart, and through it the heart understands." Job names it beside Chokhmah: "and where is the place of understanding?"
Binah is the Mother, Ima, in the language of the partzufim. It is in her that the seven lower Sefirot are conceived and carried, like children. The Talmud says that "fifty gates of understanding were created in the world, and all were given to Moses except one." The Zohar, cited by the Pardes, teaches that the Torah mentions the exodus from Egypt fifty times, corresponding to the fifty gates of Binah, to make known that the deliverance came from Binah: it is the world of freedom, the jubilee where everything returns to its origin. It is also the root of severity: judgments awaken in it, but it is the one that sweetens them.
Binah, like Keter and Chokhmah, is not in the verse of Chronicles. Elijah applies "the hidden things" to Chokhmah and Binah, and the verse begins only with the revealed Sefirot.
The trait to cultivate, according to the Tomer Devorah, is held in one word: teshuvah, return. "Binah is teshuvah," writes Cordovero, and "nothing is as important as it, for it repairs every blemish." Then he gives the rule that governs the whole chapter: "just as the way of Binah is to sweeten all judgments and to annul their bitterness, so a person shall return in teshuvah and repair every blemish." One who meditates on teshuvah all his days causes Binah to shine on all his days.
Cordovero adds something few moralists dare to say: teshuvah is good also for the evil part of a person. He cites Cain, to whom it was said "if you do well, you shall be lifted up": do not think, because you come from the side of evil, that you have no repair; "this is a lie." Every bitterness above has a sweet root, and one can climb back through that root. Thus, through teshuvah, the faults themselves become merits. His conclusion is practical: each day, a moment to think about it, and a small actual return, "so that all his days may be in teshuvah."
Keep the lesson of Binah: to understand is not only to analyze, it is to know how to come back. The mother who carried the world is also the one to whom one can always return.
