Ancient commandments and modern science converge in Shaatnez

We’ve been discussing the power of imagery in many of my recent articles, focusing on the idea of viewing everything as energy. First, because science supports this idea—and just like energy is an invisible force that transforms into matter—we can better understand and relate to God — the ineffable energy at the core of everything, present everywhere, and the cause of everything. Another point: the Torah was given to us “to improve our lives” and make the world better. There is no other way that offers the most effective route to health, happiness, and well-being than God's advice on how to achieve those things.

Let’s examine a mitzvah in the Torah and see how, from being something that might offer no immediate personal satisfaction, our great sages—namely the Kabbalists—and more recently science, help us understand the broader principle that all of God's commandments are ultimately for our benefit.

Shaatnez, the biblical prohibition against wearing garments made of both wool and linen, is a distinctive and longstanding part of Jewish law. This commandment, mentioned in Leviticus 19:19 and Deuteronomy 22:11, prohibits mixing these two fibers in a single piece of clothing. The rule is specific: it only applies when wool and linen are sewn, woven, or otherwise combined in the same garment. The law is strict and allows no leniency in quantity— even a single linen thread in a woolen garment (or vice versa) can make the entire item forbidden.

The definition here is clear: it specifically involves sheep’s wool and linen made from flax. Other fibers, such as cotton, silk, and hemp, are not included. Because of the seriousness of the prohibition, Jewish law requires certain garments—especially suits, coats, and other woolen items with hidden stitching—to be checked for shaatnez. Often, collars or even threads used to sew buttons might be made of linen, possibly causing a violation without the wearer even realizing it.

Technically, wearing two separate garments—one wool and one linen—is permitted. However, if someone puts on a linen shirt and then wears a wool sweater over it, making it impossible to remove the shirt without taking off the sweater first, many halakhic authorities consider the garments to be "joined," at least practically, and rule that this should also be avoided. Our sages teach that it is best to exercise caution in such cases—for example, by not wearing linen pants under wool ones—but the common custom today is generally lenient regarding such layering.

Now, the reason behind the prohibition is seen as a chok—a divine law with no rational explanation—similar to the laws of kashrut. Yet our sages tried to offer insight, providing both historical and mystical frameworks to help us connect to the mitzvah more deeply.

Maimonides provides a logical historical explanation that the prohibition may have originated as a way to distinguish Jews from idolatrous priests, who wore garments made of wool and linen. This helps set Jews apart from spiritually impure customs. Interestingly, the garments of the Kohanim (Temple priests) did include this wool and linen blend, but that was in the Holy Temple, where the Divine Presence was present. The holiness of the Temple was viewed as strong enough to counteract the negative spiritual effects of the mixture, showing how spiritual context can completely change the nature of something.

Kabbalistic sources like the Tikkunei Zohar and teachings cited by Rabbeinu Bachya explore this concept even further. Wool (animal sourced) and linen (plant-sourced), according to them, represent two completely opposing spiritual energies. Wearing them together causes chaos or disruption in the divine flow because it mixes energies that are never meant to be combined. It is seen as a fusion of purity with impurity, or cosmic opposites with conflicting natures, and this combination clouds spiritual clarity and harmony.

Furthermore, the Zohar plays on the Hebrew word Shaatnez as “Satan az” (“the Satan is strong”), implying that mixing these fibers strengthens negative spiritual forces or allows the evil inclination to gain influence. It is taught that an "evil spirit" may cling to someone who wears Shaatnez, reflecting deeper mystical dangers beyond the simple legal prohibition.

A well-known mystical interpretation connects the prohibition to Cain and Abel — Cain offering flax (linen) and Abel offering wool. Since Cain's offering (and behavior) is linked to lower spiritual qualities and Abel’s to higher ones, their symbolic union should be avoided. Combining the two in a garment is thus likened to mixing good and evil, purity and corruption.

Now, lo and behold, science seems to be echoing what our sages intuited thousands of years ago.

A study attributed to Dr. Heidi Yellen indicates that both wool and linen have remarkably high vibrational frequencies—measured at 5,000—compared to the average human body frequency of around 100. These elevated frequencies, according to the study, are advantageous to the wearer and can support health and vitality. However, when these fabrics are combined—either woven together or layered—their energies are said to cancel each other out, resulting in a net frequency of zero. The suggestion is that wool moves energy from left to right, while linen flows from right to left, creating a kind of energetic stalemate.

Dr. Yellen’s research, conducted with a device called the Ag-Environ machine, claims that when wool and linen are worn together, their health-promoting resonance is lost. The fabrics’ frequencies supposedly cancel each other out, and instead of gaining the energetic or healing benefits of either, the body receives nothing—or potentially worse—loses its natural energetic balance. The recommendation, based on these theories, is clear: to receive the full health benefits of these materials, each must be worn separately, not combined, even when layered. Only then can one benefit from their full vibrational potential.

Although these scientific claims are still considered unconventional, they offer an intriguing parallel to ancient religious teachings. The prohibition against mixing wool and linen—Shaatnez—thus appears not just as a mysterious religious rule but as a potential reflection of deeper energetic truths. Modern research might provide us with new language to describe what the Torah already grasped spiritually: that nothing God commands is without purpose; we might just be uncovering its wisdom gradually in our time.

The mitzvah of Shaatnez demonstrates how the Torah’s commandments—though often mysterious—are deeply connected to both spiritual balance and possibly energetic health. Whether we interpret the laws through the lens of Kabbalah or modern ideas about frequency, the prohibition reflects divine wisdom aimed at maintaining harmony within ourselves and the universe. Therefore, what once seemed like an obscure ritual restriction now serves as a gateway to greater understanding, reminding us that every commandment has meaning—whether visible or hidden—waiting to be uncovered through thoughtful study and open-hearted practice.