Why does the Bible speak against wearing clothing made of different types of fabric?

The fleece of sheep and other animals. That of sheep was used for weaving into cloth, and is generally referred to as 'wool.' In the figurative language of Isa. 1:18 undyed wool represents the state resulting from the removal of sin by Jehovah from His people; the sin being compared to that which had been dyed crimson. The law forbade the wearing of a garment made of linen and wool: it was an unnatural mixture, figurative of the working of the Spirit and the flesh in a Christian. Lev. 19:19; Deut. 22:11.

The disguise as to sex would plainly serve all kinds of fraudful and dishonest purpose, whilst it falsified the stamp which God has put upon nature, and mutilated, so to speak, the coin of His realm. The taking the mother-bird, held by her affection to her young, was shameful advantage used of natural instincts, and a violation of honor to parents in this reproduction of motherly love in the lower creatures. The repetition of the promise here is very striking. It shows how sensitive will be the really obedient heart, and how God has in nature encompassed us with remembrances as well as tests of our condition. The law as to the battlements for the flat roofs of houses is simple enough as a rebuke of that thoughtlessness which is really hardness of heart. The three laws which follow as much resemble one another as they differ from what goes before. As prohibitions of mixture they come naturally enough under the first head here. The interpretation of the unequal yoke" is plainly given in 2 Cor. 6:14. Christ's yoke cannot be borne by the unclean — the unbeliever, — and for the believer there is no other. The garment of woolen and linen speaks similarly of mixed habits; while the sowing seed represents the necessity of keeping the truth unmixed. Failure in all these points involves a real robbery, not only of God, but of one's neighbor: we owe both to Christians and the men of the world the maintenance of our Christian simplicity and singleness of life and testimony. The last thing here, the tassels upon the garment, which we have had in Num. 15:38, reminds us that this is to be true natural development — the development of the new nature, not artificial, for the word speaks primarily of flower-buds. How beautifully again does the spiritual meaning declare the perfection of the Word of God!

Peremptorily, but in wisdom, was divine order impressed, and mixture of different kinds forbidden. He is a faithful Creator, and gave to each creature its species. Hence as it was sin to separate what He joined, it was not less to join what He separated. Their cattle must gender according to the respective kind; their field must not be sown with different kinds of seed; nor was a garment woven of two materials to come on the Israelite. To the Christian the words are full of importance. It was Satan that sowed darnel with the wheat; and the Spirit warns against every incongruous communion (2 Cor. 6). There must be no diverse yoking with unbelievers, no touching what is unclean, no compromise of truth by mixed principles. In matters of this life compromise is amiable and right; but where God's will is in question, it is a ruse of the devil.

Here, however, we must close this section. We have elsewhere sought to handle the subject of "The Unequal Yoke," and shall not therefore dwell upon it here. The Israelite was not to plow with an ox and an ass together; neither was he to wear a garment of divers sorts, as of woollen and linen. The spiritual application of both these things is as simple as it is important. The Christian is not to link himself with an unbeliever, for any object whatsoever, be it domestic, religious, philanthropic, or commercial, neither must he allow himself to be governed by mixed principles. His character must be formed and his conduct ruled by the pure and lofty principles of the word of God. Thus may it be with all who profess and call themselves Christians.

Mixtures were also forbidden. Jews were not to allow their livestock to breed with other species. Mixed seed was not to be sown. Linen and wool were not to be mixed in any garment. This has typical significance such as is seen in 2 Corinthians 6:14-18, “Do not be unequally yoked together with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has light with darkness? And what accord has Christ with Belial? Or what part has a believer with an unbeliever? And what agreement has the temple of God with idols?”

Mixtures were also forbidden. Jews were not to allow their livestock to breed with other species. Mixed seed was not to be sown. Linen and wool were not to be mixed in any garment. This has typical significance such as is seen in 2 Corinthians 6:14-18, "Do not be unequally yoked together with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has light with darkness? And what accord has Christ with Belial? Or what part has a believer with an unbeliever? And what agreement has the temple of God with idols?"

In sowing a field, seeds were not to be mixed, but kept distinct (v.9). This reminds us of such truths as that of 2 Corinthians 6:14: "Do not be unequally yoked together with unbelievers." Mixtures, whether of people or of principles, are not scriptural and will lead to confusion.

Verse 10 is similar, forbidding plowing with an ox and a donkey together. Thus, a believer is not to join with an unbeliever in doing the Lord's work. Verse 11 refers to the garments worn, that two kinds of cloth were not to be used together. Garments speak of habits. Let them be clear and distinct, not compromised in any way.

The law concerning the bird's nest manifests the Creator's care and His people are to recognize it. The keeping of this law has the same promise as the commandment relating to obedience to parents. Diverse seeds were forbidden. Spiritually we find a lesson here. There are two seeds, the good and the bad. The good seed stands for the truth. It must not be mixed with error. The truth must be kept unmixed. The opposite is done today as never before in the history of Christendom. They were not to plow with an ass and an ox together. They were not to wear a mixed garment. And we are exhorted not to be unequally yoked with unbelievers, but be separated in our habits, in life and walk, unto the Lord. The concluding part of the chapter reveals the heart of man in its deceitfulness and corruption.

H.A.I. — For the sake of young believers I would give an illustration from the Old Testament; “Thou shalt not wear a garment of diverse sorts, as of woolen and linen together” (Deut. 22:11). Why? In Leviticus 7:8, we read, “The priest, that offereth any man’s burnt-offering, even the priest shall have to himself the skin of the burnt-offering which he hath offered.” I link this with Isaiah 53, “He is brought as a lamb to the slaughter, and as a sheep before her shearers is dumb, so He openeth not his mouth.” And what did the priest get? The skin of the burnt-offering — which represents what Christ is to me — my covering. “He hath made us accepted in the Beloved.” I am not to mix one thread of my own righteousness in that. The woolen garment must be unmixed. NOW read Revelation 19:8, “And to her was granted that she should be arrayed in fine linen, clean and white: for the fine linen is the righteousness of saints” — the righteousnesses, as the correct translation is; “for, the fine linen is the righteous acts of the saints.” It is a robe of fine linen — a holy life, for which we are responsible. Don’t get fine linen threads mixed with woolen. We are talking of woolen garments this morning — let us keep to that.

The Old Testament warns against wearing a garment made of linen and woolen; of sowing a field of mingled seed; of harnessing an ox and ass together; the New Testament tells us of the folly of patching an old garment with a piece of new cloth, or of putting new wine into old bottles. The linen of the Christian need not be woven with the woollen of the world, the seed of the kingdom must not be mingled with the seed of the enemy, the worn-out garment of “the old man” must not be patched by the piece of cloth of “the new man;” the new wine of joy in the Holy Ghost cannot be put into the old bottles of “the flesh.” In other words, SEPARATION is the keynote of divine life in all dispensations.