Easton's Bible Dictionary (1897)
(Gr. phulakteria; i.e., “defences” or “protections”), called by modern Jews tephillin (i.e., “prayers”) are mentioned only in Matt. 23:5. They consisted of strips of parchment on which were inscribed these four texts: (1.) Ex. 13:1-10; (2.) 11-16; (3.) Deut. 6:4-9; (4.) 11:18-21, and which were enclosed in a square leather case, on one side of which was inscribed the Hebrew letter shin, to which the rabbis attached some significance.
This case was fastened by certain straps to the forehead just between the eyes. The “making broad the phylacteries” refers to the enlarging of the case so as to make it conspicuous. (See FRONTLETS.) 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.”
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
PHYLACTERIES (preservation, or safeguard, with reference either to the preserving of the words of the Law in the memory or to the preservation of the person from danger, as by the amulets or charms of modern superstition). The practice of using phylacteries was founded on a literal interpretation of Ex 13:9, Ex 17:16; Deut 6:8; Acts 11:18, where God commands the Hebrews to bear the Law in their hearts and in their heads, and it is still continued
in our days. There are two kinds of phylacteries - one to be worn on the forehead, between the eyebrows, and another to be worn on the left arm. The former was called a "frontlet," and was composed of four pieces of parchment, on the first of which was written Ex 12:2-10; on the second, Ex 13:11-21; on the third, Deut 6:4-9; and on the fourth, Deut 11:18-21. These pieces of parchment, thus inscribed, were inclosed in a piece of tough skin, making
a square, on one side of which was placed the Hebrew letter shin, and this box was tied to the forehead with a thong or riband. Some wore them both evening and morning, and others only at morning prayer. The Phylactery. The other kind of phylacteries consisted of two rolls of parchment, written in square letters, with an ink made on purpose, and with much care. They were rolled up to a point, enclosed in a sort of case of black calfskin, and then
put upon a square bit of the same leather, whence hung a thong of the same, about a finger in breadth and about two feet long. These rolls were placed near the elbow of the left arm, and after one end of the thong had been made into a little knot in the form of the Hebrew letter yod, it was wound about the arm in a spiral line, which ended at the top of the middle finger.
Hitchcock's Bible Names (1869)
things to be especially observed