Bid them that they make them fringes. צִיצִת, probably tassels. It seems to signify something flower-like and bright, like the blooms on a shrub; the word צִיץ. is applied to the shining plate of gold upon Aaron's head-band (Exodus 28:36).
In Jeremiah 48:9 it seems to mean a wing, and in Ezekiel 8:3 צִיצִת is a lock of hair. The exact meaning must be gathered from the context, and on the whole that suggests a tassel rather than a fringe.
The word גְּדִלִיס, used in the parallel passage Deuteronomy 22:12, seems to have this meaning. The Septuagint renders it by κράσπιδα, which is adopted in the Gospels (see on Matthew 23:5). In the borders of their garments.
Literally, "on the wings," ἐπὶ τὰ πτερύγια. The outer garment ( בֶּגֶד here, כְּסוּת in Deuteronomy 22:12) was worn like a plaid, so folded that the four corners were dependent, and on each of these corners was to be hung a tassel.
It was also used as a coverlet by the poor (Exodus 22:27). That they put upon the fringe of the borders a ribband of blue. Rather, "that they put a string (or thread) of hyacinth-blue upon the tassel of the wing."
Septuagint, κλῶσμα ὑακίνθινον. This may have been a blue string with which to fasten the tassel to the corner of the garment, as if it were the stalk on which this flower grew; or it may have been a prominent blue thread in the tassel itself.
The later Jews seem to have understood it in this sense, and concerned themselves greatly with the symbolical arrangements of the blue and other threads, and the method in which they were knotted together, so as to set forth the whole law with all its several commandments.
The later Jews, however, have always contrived, with all their minute observance, to break the plain letter of the law: thus the modern talith is an under, and not an upper, garment.