Tefillin are two small black boxes with black straps attached to them; Jewish men are required to place one box on their head and tie the other one on their arm each weekday morning. Tefillin are biblical in origin, and are commanded within the context of several laws outlining a Jew's relationship to God. "And you shall love the Lord your God with all your heart, with all your soul, and with all your might. Take to heart these instructions with which I charge you this day. Impress them upon your children. Recite them when you stay at home and when you are away, when you lie down and when you get up. Bind them as a sign on your hand and let them serve as a frontlet between your eyes" (Deuteronomy 6:5-8).
Certain Jewish groups including probably the Sadducees, and definitely the medieval Karaites understood the last verse to be figurative; it means only that one should always be preoccupied with words of Torah, as if they were in front of one's eyes. The Pharisees, however, took the text literally; the words of the Torah are to be inscribed on a scroll and placed directly between one's eyes and on one's arm. Tefillin are wrapped around the arm seven times, and the straps on the head are adjusted so they fit snugly.
The text that is inserted inside the two boxes of Tefillin is hand-written by a scribe, and consists of the four sets of biblical verses in which Tefillin are commanded (Exodus 13:1-10, 11-16; Deuteronomy 6:4-9, 11:13-21). Because each pair of Tefillin is hand-written and hand-crafted, it is relatively expensive, and a well-made pair costs several hundred dollars.
The word Tefillin is commonly translated as "phylacteries," though the Hebrew term is more often used. I have never met a Jew who puts on Tefillin who calls them "phylacteries."
Putting on Tefillin is the first mitzvah assumed by a Jewish male upon his Bar Mitzvah. Usually, boys are trained to start wearing them one to two months before their thirteenth Hebrew birthday. During the training period, boys don Tefillin, but do not recite a blessing. Subsequent to the Bar Mitzvah, a specific blessing, "Blessed are You, Lord our God, King of the universe, who has sanctified us with His commandments and commanded us to put on Tefillin, " is recited whenever they are worn. Many Jews say an additional blessing and prayer upon putting on Tefillin.
Tefillin are worn each weekday morning, but not on the Sabbath or on most Jewish holidays. On the fast day of Tisha Be'Av, and on that day only, they are put on during the afternoon instead of the morning service.
Among observant Jews, Tefillin is a mitzvah of the greatest significance. Recently, an eighty-nine-year-old rabbi told me that, in the seventy-six years since his Bar Mitzvah, he had not missed putting on Tefillin even once. Since the Holocaust, stories have circulated of Jews who managed to smuggle Tefillin into Nazi concentration camps and put them on each morning.
One Jewish group, the Lubavitcher Hasidim, have made a particular effort to promote the mitzvah of Tefillin among Jewish males. They often set up vans, known as Mitzvah Mobiles, in neighborhoods frequented by Jews, and ask men who pass by: "Are you Jewish?" If the answer is yes, they continue: "Did you put on Tefillin today?" If the person says, "No," they invite him inside the van. First they put on the box that goes on his arm (for right-handed people, the Tefillin go on the left arm; left-handed people wear them on the right arm) and wrap the strap around the arm seven times. Then the other box is put on his head. They lead him in the recitation of the blessing over the Tefillin, and in certain other major prayers, such as the Sh'ma.
Many years ago, the Lubavitcher Rebbe advised the world-famous sculptor Jacques Lipchitz to start wearing Tefillin and to pray every morning. Lipchitz subsequently described the effect of these two acts on his life: "I daven [pray] every morning. It is of great help to me. First of all, it puts me together with all my people. I am with them. And I am near to the Lord, the Almighty. I speak with Him. I cannot make my prayers individual, but I speak to Him. He gives me strength for the day.... I could not live anymore without it."