That ye may remember, and do all my commandments, and be holy unto your God.

Wesley's Notes

15:40 Be ye holy - Purged from sin and sincerely devoted to God.

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.