phylacteries (fĭlăkˈtərēz) [key] [Gr., = safeguard], two small leather boxes worn during morning prayers by Orthodox and Conservative Jews after the age of 13 years and one day. Each box contains strips of parchment inscribed with verses from the Scriptures: Ex. 13.1–10; 13.11–16; Deut. 6.4–9; 11.13–21. One box is fastened to the forehead and the other to the left arm; they are intended to serve as a reminder of the constant presence of God and of the need to keep Him uppermost in one's thoughts and deeds, thereby safeguarding the wearer against committing a sin. They are not worn on the Sabbath or holy days, since these days are in themselves a reminder of God. Phylacteries are also called tephillin [Aramaic, = attachment].