(Gr. phulakteria; i.e., "defences" or "protections"), called by modern Jews tephillin (i.e., "prayers") are mentioned only in Matthew 23:5 . They consisted of strips of parchment on which were inscribed these four texts:
Another form of the phylactery consisted of two rolls of parchment, on which the same texts were written, enclosed in a case of black calfskin. This was worn on the left arm near the elbow, to which it was bound by a thong. It was called the "Tephillah on the arm."
things to be especially observed