SISITH. - “Tassels” which, together with the gèdhilim (“fringes”), the Israelites place at the corners of their outer garments (Num. 15, 37-41); the blue cord with which the tassel at each corner is to be attached must remind them of the commandments of the Lord. Deut. 22, 12 prescribes the gèdhilim at the four extremities of the mantle.
The practice is very ancient; it seems to us to be a remnant of knot-writing. The blue was perhaps intended (as the ancient rabbis believed) to recall the sky. It was a custom rigorously inculcated by the Pharisees (Mt. 23, 5). In the diaspora, people began to wear a special small garment with tassels beneath their outer garments, reserving tassels and blue-coloured stripes for the mantle (talèth) to be worn during public prayers. The blue cord was abolished, since it was originally purple in colour, obtained from a small worm, an industry that had fallen into disuse.