The Jewish way of life is based on the teachings of the Torah- that Bible given by G-d to the Jewish people at Sinai a few millennia ago. The written teachings of the Bible, accompanied by the oral teachings of the Rabbis on the Bible are what Jewish people live their lives according to.
One of the laws relating to clothing in the Jewish way of life is the prohibition in the Torah against wearing clothes containing a mixture of wool and linen. The sages provided a number of reasons for this law with the author of the book “Sefer HaChinuch” suggesting that the combination of certain worldly materials can cause havoc in the spiritual realm.
Another explanation that is offered for this prohibition is that when Kain and Abel brought their offerings before G-d, one brought flax and the other a sheep and due to the lethal mixture Abel ended up losing his life.
In any event, Shatnez is recognized as a “Chok”- a Jewish law that Rabbis can offer suggestions for the reasoning behind it but in actually is a law that cannot be explained. Shatnez is still applicable today and therefore Jewish people will often send new clothing to be checked in special Shatnez laboratories so as to check that the clothing doesn’t contain the forbidden mixture.
Men’s Clothing, Women’s Clothing
In ancient times, both men and women would wear robes- with different robes made for men and women. There is a commandment in the Torah that states that a man must not wear woman’s garment and a woman may not wear a man’s. An explanation offered for this commandment by the author of Sefer HaChinuch is that this law is to prevent intermingling between the sexes leading to licentiousness. This law is still upheld by observant Jews- in such communities the women will never wear trousers and the men will not wear tight clothing (considered to be more “feminine”).
Observant Jewish men wear a head covering at all times during the day. This practice is actually a custom that became an accepted law due to the wide-spread acceptance of it. In earlier days only the very righteous would wear head-coverings to show awe of G-d Who is above them but nowadays every Jewish male from the age of three wears a head covering. The head covering is called Kippah in Hebrew and Yarmulke in Yiddish. It serves as a constant reminder of G-d’s Presence and is worn by men and not women because it is recognized in Judaism that men are more in need of external reminders of G-d as opposed to women who are spiritually on a higher level.
Ritual Fringes is another garment worn exclusively by Jewish males and is based on a commandment in the Torah. The Jewish Sages interpreted the source to mean that from the age of three Jewish males must wear a garment under their clothes that has four corners and on each of the corners a set of fringes. These fringes act as a constant reminder of G-d’s Presence and every morning the Jewish male recites a blessing over them. This is a time-bound commandment- that can only be carried out in the day and women in Judaism are not obligated to uphold time-bound commandments so are not obligated in the wearing of the fringes that are known in Hebrew as Tzitzit.
An important concept in Judaism is that of modesty- modesty as a way of life- including how one dresses, speaks and acts. After the sin in the Garden of Eden man and woman became aware of their being made up of physicality and spirituality (before-hand they were on a spiritual level whereby they only saw the other as a spiritual being) and as a result started to base the way they looked at each other on their external appearances. Ever since then mankind has covered themselves and Judaism sees great importance in dressing in a clean, tidy, beautiful way as befitting people of the King (G-d) but also believe that clothing should not be flashy in a way that would cause people to concentrate solely on external beauty.