Comentario sobre Deuteronómio 22:12

גדלים תעשה לך THOU SHALT MAKE THEE TASSELS [UPON THE FOUR CORNERS OF THY VESTURE] — be they even from a mixture of wool and linen; for this reason Scripture puts them (the prohibition of שעטנז and the command of צצית) in juxtaposition (Yevamot 4a).

גדילים, tzitzit, fringes, their threads have to be intertwined.

גדלים תעשה לך , you shall make for yourselves twisted threads;” here the tzitzit are referred to as gedilim. Our sages in Yevamot 4 cite a tradition that the appearance of this commandment in a positive connotation immediately after the prohibition of mixing wool and linen is to teach us that for the purpose of tzitzit this prohibition has been waived. The Talmud concludes that the appearance of certain legislation immediately after another legislation has halachic implications and is a legitimate exegetical tool (דרשינן סמוכים). The reasoning goes as follows: “if the Torah had not wanted to permit a mixture of wool and linen threads as the integral parts of the tzitzit, why would the prohibition of kilayim have to be repeated here? We already discussed the mystical aspect of the commandment of making and wearing tzitzit in Numbers 15,38.
The expression גדלים chosen by the Torah here to describe these tassels, fringes, is an allusion to Psalms 104,1: ה' אלו-הי גדלת מאד הוד והדר לבשת, “O Lord, my G’d, You are very great; You are clothed in glory and majesty.” When someone wears tziztiyot, i.e. 32 twisted threads, this is an allusion to the 32 paths of wisdom (discussed in the latter part of Numbers 15,38)