Phylacteries or tefillin, are two small black leather boxes worn on the left arm and forehead by observant adult male Jews. The leather boxes of the tefillin contain scrolls of Torah passages, specifically Exodus 13:1-10, 11-16 and Deuteronomy 6:4-9, 11:13-21. These passages command Jews to bind the word of God on their bodies.

"And you shall bind them as a sign on your arm, and they shall be as frontlets on your head between your eyes." (Deuteronomy 6:8) Certain Jewish groups, including probably the Sadducees, and definitely the medieval Karaites, understood the command to be figurative: 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.

Today, observant Jews wear tefillin both in literal obedience to these Torah verses and to remind the wearer of God's commandments.

Terms and Etymology

The word tefillin is translated phylacteries in English. This word derives from the Greek φυλάσσειν (phylassein), meaning "to guard against evil" or "to protect," suggesting a protective amulet. But the Hebrew word tefillin is related to the word tefilah (prayer) and the Greek term was not used in Jewish circles. Modern Jews generally prefer the word "tefillin." (As Rabbi Telushkin puts it, "I have never met a Jew who puts on Tefillin who calls them "phylacteries.") Both tefillin and phylacteries are plural words, and refer to both boxes. A single leather box is a tefillah or phylactery. The arm tefillah is called the shel yad and the head tefillah is called the shel rosh.

Form and Specifications of Tefillin

The leather boxes must be made from the skin of kosher animals. The boxes must be exactly square, and dyed black. The measurements of the boxes and straps are not specified, but it is recommended that the boxes be no smaller than the width of two fingers.

Like the scrolls in a mezuzah, the scrolls in tefillin must be written in Hebrew in a special style of writing. The hand tefillah has all four passages on one scroll, while the head tefillah has them on each of four separate parchments. The latter are fastened together with the thoroughly washed hair of a kosher animal, preferably of a calf.

Who Wears Tefillin?

The commandment to wear tefillin is binding on Jewish males 13 years of age or older. Women are exempt from the obligation, as are slaves. Early Jewish law codes allowed women to take on the obligation of wearing tefillin, but this custom was generally discouraged. Over time the discouragement changed into active exclusion, especially amongst Ashkenazi Jews.

Modern Orthodox Judaism holds that it is permissible for women to wear tefillin, but generally discourage it. Conservative Judaism and Reform Judaism allow women to wear tefillin. Many in Conservative Judaism encourage this practice.

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 if they are Jewish, and if so, if they are wearing tefillin. If not, they help him to put on tefillin and teach him the blessings. Lubavitcher Hasidim are also present every day at the Western Wall in Jerusalem, encouraging Jews to fulfill the mitzvah of tefillin.

How to Wear Tefillin

At weekday morning services, the tefillin are put on in an exact manner: first one box is tied to the arm, with the scrolls at the biceps and leather straps extending down the arm to the hand, then the other box is tied to the forehead with the straps hanging down over the shoulders. For right-handed people, the tefillin go on the left arm; left-handed people wear them on the right arm.

As with all Jewish rituals, blessings are recited during this process. Before putting on the arm tefillah, the wearer says, "Blessed are you, Lord, our God, King of the universe, Who has sanctified us with His commandments and has commanded us to put on tefillin." After the head tefillah is tightened, he recites, "Blessed is the Name of His glorious kingdom for ever and ever."

The strap that is passed through the head tefillah is knotted at the back of the head, forming the Hebrew letter ד; the strap that is passed through the hand-tefillah is formed into a noose near the box and fastened in a knot in the shape of the letter י. The box of the head tefillah has on the outside the letter ש, both to the right and to the left. Together, these form the Hebrew word Shaddai ("Almighty"), one of the names of God.

Tefillin are usually removed at the conclusion of the morning services. Some Jews wear them all day, except on the Sabbath and festivals.

Because they are hand-crafted, a valid set of tefillin can cost several hundred dollars (and even over a thousand), but if properly cared for they can last for a lifetime.

When not being worn, tefillin are rolled up and placed in a tefillin bag, usually made of silk or velvet and beautifully embroidered.


  • Rabbi Joseph Telushkin, Jewish Literacy (1991).
  • "Phylacteries." JewishEncyclopedia.com.
  • "Signs and Symbols." Tracey R. Rich, Judaism 101 (accessed 2006).
  • "Tefillin." John R. Hinnells, ed., Penguin Dictionary of Religions (1995).

More Information on Tefillin

  • Tefillin Guide - Chabad.org (includes reference works on tefillin)
  • STAM - Maker of tefillin and mezuzah scrolls
  • How to lay tefillin - Davening.net
  • Photo of old family phylacteries with explanation - "E-Journeys" at Flickr.com

Article Info

Title tefillin
Last UpdatedJanuary 29, 2021
URL religionfacts.com/tefillin
Short URLrlft.co/1048
MLA Citation “tefillin.” ReligionFacts.com. 29 Jan. 2021. Web. Accessed 23 Jan. 2022. <religionfacts.com/tefillin>