When we first seriously consider trying to obey all of Torah, as much as we can anyway, we’re confronted with commands which seem arbitrary and difficult, such as the law governing the kinds of materials used in clothes. It appears twice: “neither shall a garment mingled of linen and woollen come upon thee” (Le 19:19), and “Thou shalt not wear a garment of divers sorts, as of woollen and linen together.” (De 22:11)
The topic initially raises eyebrows for the submitted believer, since most of the clothing we wear today contains a mixture of fiber types. Garments of cotton and polyester are quite common, inexpensive, durable and comfortable. Why would God forbid clothing like this?
In order to get back to a reasonable place, we must, as always, read this command VERY carefully. In both instances, the kind of diversity forbidden is specified very explicitly and clearly; and for anyone who knows anything about textiles, it’s no surprise. The command does not forbid mixing just any two kinds of fibers, but fiber types that are distinctly different in fundamental, incompatible ways. The example given is linen and wool.
Textile manufacturers understand that wool and linen are fundamentally incompatible: linen is a plant-based fiber that creases easily and wool is an animal-based fiber that shrinks easily. The two types of materials also wear very differently and require very different types of care. Wool requires a different type of storage than linen due to susceptibility to mold and moths, and a different cleaning protocol to keep it from shrinking. When only a portion of the fibers of a garment shrink while other fibers don’t the entire structure and weave of the fabric is compromised.
Further, recent scientific studies have confirmed that wool and linen have very strong electrical properties when reacting with light, and these two materials happen to work in opposite polarities. By themselves, garments of either wool or linen tend to energize the human body electrically and even provide healing benefits, but together these materials work against each other and cancel each other out. This effect tends to sap the strength of the wearer and may even cause discomfort or blistering. Any garment made from these two materials would be difficult to care for and unhealthy to wear.
God knows what He’s doing when He gives us commands; His laws are good (Ro 7:12), but if we aren’t careful we may easily misapply them and cause ourselves and others needless inconvenience. (Lk 11:46) When we interpret Torah, we must do so lawfully (1Ti 1:8), being careful to keep it in full context, and in accord with the law of love. When God’s law appears overly burdensome, it’s likely we’re missing something basic: His yoke is easy and His burden is light. (Mk 11:30)