Musar zu Schir haSchirim 2:2

All the wicked people surround Jerusalem, as is written: כל גויים סבבוני, "All the Gentile nations surround me" (Psalms 118,10). Jerusalem can be compared to the "lily amongst the thorns," Solomon's description of Israel in Song of Songs 2,2. Because terrestrial Jerusalem is surrounded by such secular turbulence, the ערלה in the emanation יסוד has to be removed as a first step so that the covenant called ברית המעור, the mystical root "סוד" of the emanation יסוד can be revealed and the עטרה be laid bare.

In the world there are trees and herbs and good and bad fruit. Some of them have a pleasant aroma and fruit that is good for nourishment and healing. And there are herbs and roots and fruit that can slay, like the herbs which produce deadly poison or like the thorn and the thistle. The good flora may be compared to good people, as it is written, "As a lily among thorns… As an apple tree among the trees of the wood" (Cant. 2:2—3). And the evil flora to evil people, as it is written, "But the ungodly, they are as thorns thrust away" (II Sam. 23:6).