Within every man, a great river flows. More than a river---a great river system, with dozens of major arteries, hundreds of tributaries, thousands of rivulets and tens of billions of minute channels. Fourteen-hundred times every day, this great river system--laid end to end it would extend some 60,000 miles--carries its life-sustaining fluid to every cell of the human body, supplying it with oxygen and nourishment, carrying off wastes, and combating adversarial cells that seek to harm it.
Man is a metaphor. Indeed, one of several meanings of the Hebrew word adam ("man") is "I resemble." For man is a microcosm of creation---in the words of the Talmud, "As the soul fills the body, so G‑d fills the universe." Thus Job declares, "From my flesh, I perceive G‑d"--by contemplating the workings of my body and the manner in which it relates to and is animated by my soul, I gain insight into the workings of creation and the manner in which it relates to and is sustained by its supernal source.
The Torah is the "blood" of the cosmic body. Torah is the flow of divine influence that extends to every "cell" of creation, imbuing it with the breath of life, nourishing and developing it, and combating the negative forces that threaten to corrupt it.
The Red Priority
The two primary active ingredients of human blood are the erythrocytes, or red blood cells, and the leukocytes, or white blood cells. The red blood cells carry oxygen to the body's cells. The white blood cells combat infection and resist the invasion of bacteria and other foreign bodies.
The Torah also has its "red blood cells" and "white blood cells," its nutritive and combative elements. By instructing and enlightening our lives, the Torah sustains and matures our spiritual essence, developing in us, and in the environment we inhabit and interact with, the potential for goodness and perfection that G‑d imparted to His creation. The Torah also combats evil with a series of prohibitions and sanctions against practices that compromise the spiritual integrity of the body-universe.
But the greater emphasis is on the positive, nurturing role. The Torah's "ways are pleasant, and all its paths are peace" (Proverbs 3:17). Combating evil is still an unfortunate necessity--until the day that "the spirit of impurity shall cease from the earth"--but it is not what Torah is about; the gist of Torah's role is to imbue our lives with spiritual sustenance. This priority is also reflected in the human metaphor of the cosmic bloodstream: the 25-trillion red blood cells in the human body outnumber its white blood cells by a ratio of 700 to 1.
In discussing the flow of divine influence into our world, Kabbalistic teaching speaks of a phenomenon it calls "the reversal of mediums" (achlifu duchtaihu). For example, at times it is deemed necessary for "benevolence to come in a vessel of severity, and severity in a vessel of benevolence."
The best way to understand this principle is to examine how this applies, on the human level, to our relationships with others. Love is the drive to give and come close to another; an overdose of love, however, may distance rather than bring close and harm rather than assist. If a father were to hug his child with the full intensity of his love for him, he would cause him grievous hurt; indiscriminate charity may foster dependence and low self-esteem on the part of the recipient, to his own ultimate detriment. Thus, love must often be packaged in a "vessel of severity" and restraint. The same applies in the reverse: when it is necessary to discipline and restrain, one must channel severity via a "vessel" of benevolence. Justice that is not administered with compassion may cause the very opposite of what it comes to achieve, breaking the transgressor it comes to rehabilitate and destroying the society it comes to preserve.
The same applies, on the physical level, to the "benevolent" and "severe" cells in our bloodstream. The red blood cells have an extremely complex structure, designed to regulate the quantity and manner of its nourishment of the body's cells; otherwise, they would oxidize rather than oxygenate them. In other words, the "vessel" that carries this giving influence must be designed to regulate and withhold, lest the benevolence it dispenses cause the very opposite of what it is meant to achieve. The reverse is true of the combative white blood cells: their "severity" is tempered and contained by a vessel of "benevolence," lest they destroy good cells along with the bad and poison the body with their toxicity.
Therein lies the deeper significance of the colors of the various blood cells. The nourishing cells are colored red, the color associated in Kabbalah with the divine attribute of judgment and severity (gevurah), reflecting the fact that their benevolent function must be "colored" by restraint. On the other hand, the combative cells are colored white--the supernal hue of chessed, the divine attribute of benevolence and love--indicating that this potent force must by administered via a gentling "vessel."
Thus it is with Torah, the lifeblood of the universe. Torah brings the divine into our lives, yet imparts it as ideas, experiences and deeds that are incorporable into our human, finite selves. Were it not for this "packaging" our humanity and individuality would be utterly nullified before the all-transcending, all-pervading, divine essence invested in the Torah; but in the form of Torah's "red blood cells" we can ingest and internalize the divine nourishment, fusing the cosmic body to its supernal soul.
In its combative role, Torah is utterly intolerant of evil. But it is tolerant of human frailty, repelling corruption without destroying the corrupted. It implements its exacting standards of virtue and truth in the form of "white blood cells"--via a vessel of benevolence and compassion.