רֹאשֵׁ֤ךְ עָלַ֙יִךְ֙ כַּכַּרְמֶ֔ל וְדַלַּ֥ת רֹאשֵׁ֖ךְ כָּאַרְגָּמָ֑ן מֶ֖לֶךְ אָס֥וּר בָּרְהָטִֽים׃
La tua testa su di te è come il Carmelo e i capelli della tua testa come viola; Il re è tenuto prigioniero nelle sue trecce.
Zohar
The tenth precept is to put on Tefilin, and to complete himself with the supernal image. As it is written, "And Elohim created man in His own image" (Genesis 1:27). He opened the discussion by saying: "Your head upon you is like the Carmel" (Song of Songs 7:6). This verse has already been explained. Nevertheless, "Your head upon you is like the Carmel" applies to the supernal head - the Tefilin worn on the head of the holy Supernal King Yud Hei Vav Hei that appears in the written letters: Each letter is equivalent to one paragraph. The Holy Name is engraved according to the proper order of the letters. And we have learned that the verse "that you are called by the name of Hashem, and they shall be afraid of you" (Deuteronomy 28:10) refers to the Tefilin of the head, which represent the Holy Name, according to the order of the letters.
Zohar
The Tefilin are actually the letters of the Holy Name. Therefore, "Your head upon you is like the Carmel" - the Tefilin of the head. "And the hair (Heb. dalat) from dalah (poor) of your head" (Song of Songs 7:6) refers to the Tefilin of the hand, as she is poor, in comparison to above. Thus, she achieves perfection as above!
Zohar
"a king is caught in its tresses" (Ibid. 6), that he is tied down and tightly held in those compartments for the purpose of being properly united with that Holy Name. Therefore, whoever puts them on receives the image of Elohim. Because just as Elohim is united with the Holy Name, so does the person who puts them on become united with the Holy Name accordingly. "Male and female He created them" (Genesis 1:27) - the Tefilin of the head and the Tefilin of the hand - and all is one (the same)!