Matthew 23:5

Make broad their phylacteries] Every male Jew above the age of thirteen was required to say both morning and evening, except on sabbaths and feasts, when the synagogue services took their place, 'the prayers of the phylacteries.' The phylacteries themselves were cubical boxes (size from ½ in. to 1½ in.), made of the skin of a clean animal, and attached to a broad strip of material, by which they were bound to the body at prayer-time. Two were worn. The head-phylactery was so fastened to the brow that the prayer-box came between the eyes. This was the one which the Pharisees made broad, i.e. as large and conspicuous as possible. The arm-phylactery was tied round the left arm on the inside, so as to be near the heart, and during use was invisible, being covered by the sleeve. The head-phylactery was divided into four compartments, containing on little rolls these four portions of scripture: Exodus 13:1; Exodus 13:11; Deuteronomy 4:4; Deuteronomy 11:13. The arm-phylactery contained the same passages written on a single roll. The rabbis held these phylacteries, or tephillin, in the highest veneration. They were to be kissed when put on or off, they were holier than the frontal of the high priest's mitre, they were a preservative against demons, whence their name phylacteries, i.e. amulets (from a Gk. word meaning 'to guard'). They were sworn by, by touching them. God Himself was said to wear them, and to swear by them when He swore by 'His holy arm.' Orthodox Jews find the wearing of the phylacteries commanded in the Law (Exodus 13:9; Deuteronomy 6:8; Deuteronomy 11:18), but the Karaite Jews dispute the interpretation and do not wear them. The phylacterial prayers being said at stated times, the Pharisees would arrange to be seen saying them in public, at the 'corners of the streets': see on Matthew 6:5. The borders] or, rather, 'holy tassels': see on Matthew 9:20. In our Lord's time they were worn publicly on the four corners of the outer garment. Modern Jews wear them secretly on an under garment called a tallith, for fear of ridicule. In the synagogue a second and larger tallith is worn during the prayers to cover the head and neck. This tallith, or prayer-veil, was perhaps in use in our Lord's time.