Albert Barnes Commentary Matthew 23:5

"But all their works they do to be seen of men: for they make broad their phylacteries, and enlarge the borders [of their garments]," — Matthew 23:5 (ASV)

Their phylacteries. The word phylactery comes from a word signifying to keep, preserve, or guard. The name was given because phylacteries were worn as amulets or charms, and were supposed to defend them from evil. They were small slips of parchment or vellum, on which were written certain portions of the Old Testament. The practice of using phylacteries was founded on a literal interpretation of the passage where God commands the Hebrews to have the law as a sign on their foreheads and as frontlets between their eyes (Exodus 13:16; Proverbs 3:1, 3).

Proverbs 6:21. One kind of phylactery was called a "frontlet" and was composed of four pieces of parchment: on the first was written Exodus 12:2-10; on the second, Exodus 12:11–21; on the third, Deuteronomy 6:4–9; and on the fourth, Deuteronomy 11:18–21.

These inscribed pieces of parchment were enclosed in a piece of tough skin, forming a square. On one side of this square the Hebrew W letter shin was placed—and they bound them around their foreheads with a thong or ribbon when they went to the synagogue. Some wore them evening and morning, and others only at the morning prayer.

As the token on the hand was required, as well as the frontlets between the eyes, the Jews made two rolls of parchment, written in square letters with specially made ink and with much care. These were rolled up to a point and enclosed in a kind of case of black calfskin. They were then put on a square piece of the same leather, from which hung a thong of the same material, about a finger's width and about two feet long.

These rolls were placed at the bend of the left arm. After one end of the thong had been made into a little knot in the form of the Hebrew letter ? yod—it was wound around the arm in a spiral line, ending at the top of the middle finger. The Pharisees enlarged their phylacteries, making them wider than others did, either so they could make the letters larger or write more on them—to show, as they supposed, their particular reverence for the law.

Enlarge the borders of their garments. This refers to the loose threads that were attached to the borders of the outer garment as a fringe. This fringe was commanded to distinguish them from other nations and that they might remember to keep the commandments of God (Numbers 15:38–40; Deuteronomy 22:12). They made them broader than others did, to show that they had particular respect for the law.