Speak unto the children of Israel, and bid them that they make them fringes in the borders of their garments throughout their generations, and that they put upon the fringe of the borders a ribband of blue:

Wesley's Notes

15:38 Fringes - These were certain threads or ends, standing out a little further than the rest of their garments, lest there for this use. In the borders - That is, in the four borders or quarters, as it is, Deut 22:12. Of their garments - Of their upper garments. This was practiced by the Pharisees in Christ's time, who are noted for making their borders larger than ordinary. A ribband - To make it more obvious to the sight, and consequently more serviceable to the use here mentioned. Of blue - Or, purple.

Scofield Reference Notes

[1] ribband of blue

The ribband of blue. Blue, the heavenly colour, used upon the borders of the priests' garments signified that the servants of God were to be heavenly in obedience and character, and separate from earthly ambitions and desires.

Jamieson-Fausset-Brown Bible Commentary

38. bid them that they make them fringes in the borders of their garments-These were narrow strips, in a wing-like form, wrapped over the shoulders and on various parts of the attire. "Fringe," however, is the English rendering of two distinct Hebrew words-the one meaning a narrow lappet or edging, called the "hem" or "border" (Mt 23:5; Lu 8:44), which, in order to make it more attractive to the eye and consequently more serviceable to the purpose described, was covered with a riband of blue or rather purple color; the other term signifies strings with tassels at the end, fastened to the corners of the garment. Both of these are seen on the Egyptian and Assyrian frocks; and as the Jewish people were commanded by express and repeated ordinances to have them, the fashion was rendered subservient, in their case, to awaken high and religious associations-to keep them in habitual remembrance of the divine commandments.

Matthew Henry's Concise Commentary

15:37-41 The people are ordered by the Lord to make fringes on the borders of their garments. The Jews were distinguished from their neighbours in their dress, as well as in their diet, and thus taught not to be conformed to the way of the heathen in other things. They proclaimed themselves Jews wherever they were, as not ashamed of God and his law. The fringes were not appointed for trimming and adorning their clothes, but to stir up their minds by way of remembrance, 2Pe 3:1. If they were tempted to sin, the fringe would warn them not to break God's commandments. We should use every means of refreshing our memories with the truths and precepts of God's word, to strengthen and quicken our obedience, and arm our minds against temptation. Be holy unto your God; cleansed from sin, and sincerely devoted to his service; and that great reason for all the commandments is again and again repeated, I am the Lord your God.