The Torah is speaking metaphorically. The heart is the seat of emotion and desire. As long as one has not cut away the spiritual dross that surrounds his heart, his trend towards sinful behavior continues unabated. If one addresses his impulses and desires, puts them in check, he weakens their ability to cause him to gravitate towards sin. Ibn Ezra puts it, “One must distance himself from the thick and heavy desires (that weigh down on him) like an orlah, uncircumcised foreskin. Alternatively, it might mean that one should purify his heart, so that he understands the truth.”
Essentially, Ibn Ezra teaches us that if one does not prepare himself; if he does not cleanse his heart of moral/spiritual impurity, he is unable to come close to Hashem. As an uncircumcised male is missing completion, so, too, will he who has not removed the moral filth covering his heart be able to retain a close affiliation with Hashem and His Torah. Taharas ha’lev, purifying the heart, freeing oneself from his blighted character traits, is a requisite for spiritual ascendancy. There are those who have successfully embraced Torah observance after years of alienation, assimilation, and moral deprivation. Some make it; some do not. They walk the walk, talk the talk, but never really make it. Why? It is their orlas ha’lev that prevents an enduring relationship with the Almighty. As long as there remains a deficiency in their middos, character traits, they remain spiritually “short” of their intended goal, of becoming a ben Torah. In order to have it “all”, one must give up “all” that weighs him down.
