The Torah, “Exodus” (Tetzave), 28:39, 28:42: You shall make the linen tunic of checker work, and you shall make a linen cap, and you shall make a sash of embroidery work…And make for them linen pants to cover the flesh of [their] nakedness; they shall reach from the waist down to the thighs.
It is talking about corrections which come from inside of a person and appear in this allegory.
A sash that is mentioned in Torah is different from a regular sash in the way that it covers the body from the top and separates the top part from the bottom part. The top part is Galgalta Eynaim, the bestowing desires. The lower part is the receiving desires.
Nakedness is a desire to receive which can be corrected only partially. Therefore, only after the correction of the upper part, which is symbolized by the tunic, turban, and sash, one can start correcting the lower part in a partial way: from the waist to the knees. This means the correction of the receiving desires.
Those desires that are located even lower almost do not become corrected. Their use is simply stopped since one performs a restriction on their use. This is sufficient.
From KabTV’s “Secrets of the Eternal Book,” 8.28.13