Rashi defines cck iuvn, as obstruction or numbness of the heart. This refers to a spiritual numbness which brings about a weakening and crippling effect on one’s faith which prevents him from viewing life clearly through a Torah perspective. Troubles befall a person and he wonders why? He doesn’t recognize Hashem’s binding force in everything that transpires. While numbness of the heart is a result of sin, it is also a basis for future sin and a prime hindrance for performing teshuva (repentance). Thus do we say in the very last “Al Chayt” of the Yom Kippur confession: “And for the sin which we have sinned before you with numbness of the heart”.
There are times when such numbness is surmounted, and one is awakened from his spiritual slumber to perform teshuva. However, it is precisely at such moments that the satan approaches from a new angle, insisting that the individual rescind his desire to repent, for he has strayed too far to the point of no return. This feeling of depression brought about by the satan has succeeded in deterring many from successfully returning to Hashem. Individuals in such a situation, aware of their enormous sense of guilt, cannot conceive a mercy so great as Hashem’s which is great enough to pardon their sins. Hashem desires that we take the initial step towards Him, He then guides us through the process of sincere and genuine teshuva.