The tefillin (תפילין), also called phylacteries in Greek, are two small square black leather cases with straps on one side, used during the morning prayer (shachrit). Belts (retzu'ot), also in black leather, are used to fasten the tefillin. One of the cases, called shel yad (for the arm), is fastened around the left arm (or right arm if you are left-handed); the other one, called shel rosh (for the head), is placed on the head. Both cases contain the four passages of the Pentateuch from which the commandment of the tefillin is taken (Ex. 13:9; 13:16; Deut. 6:8; 11:18). The passages are copied by a scribe (sofer) who uses a single parchment for the arm case (with one large compartment), and four separate parchments for the head case (which has four compartments). On both sides of the head case the Hebrew letter shin (ש) appears. The head strap knot forms the letter dalet (ד), while the strap passing around the arm case has a knot in the shape of the letter yod (י). These three letters create the name Shadday (שדי), one of the sacred names of God.

The tefillin knots are endowed with a highly symbolic value. The word itself, an Aramaic term, is associated with the Hebrew term tefillah, “prayer”, while the practice is seen as a symbolic knot, a bond between the devoted and God. All Jewish men, from the coming of age ceremony at thirteen, are required to wear the tefillin. They are usually donated by the family along with the tallit, to the young man who has become a bar mitzvah (literally a son of the commandment), the ceremony which marks the entry of Jewish men into the community. Originally tefillin were worn throughout the day, from morning to late evening, but not at night. Today the custom is to wear them only during the morning liturgical service. They are not worn during the bread or during other religious holidays. Discover the tefillin donated to the Jewish Museum Lecce: