762. Degrees of Aviut

What is the difference between Aviut [thickness] Shoresh [root], called Salik BeRe’uta [lit. Ascended in desire. (from Aramaic): wanted], and Aviut of Behina Aleph [first discernment], called Histaklut Dak [lit. thin looking]? It is that in Aviut Shoresh, the light of Nefesh is clothed, and in Histaklut Dak, the light of Ruach is extended.