A relatively small case containing four portions of the Law (Ex 13:1-10, 11-16; De 6:4-9; 11:13-21) and worn by Jewish men on their forehead and left arm. Concerning the practice of wearing such cases, or phylacteries, The Jewish Encyclopedia (1976, Vol. X, p. 21) observes: “The laws governing the wearing of phylacteries were derived by the Rabbis from four Biblical passages (Deut. vi. 8, xi. 18; Ex. xiii. 9, 16). While these passages were interpreted literally by most commentators, . . . the Rabbis held that the general law only was expressed in the Bible, the application and elaboration of it being entirely matters of tradition and inference.”

Christ Jesus censured the scribes and Pharisees for ‘broadening the scripture-containing cases that they wore as safeguards.’ (Mt 23:5) By enlarging these cases, they apparently wanted to give others the impression that they were very zealous and conscientious about the Law. Jesus’ words indicate that the religious leaders viewed these cases as safeguards, or charms. The Greek word phy·la·kteʹri·on, in fact, primarily means an outpost, fortification, or safeguard.​—See FRONTLET BAND.