The Midrash says that for each moment in which a person refrains from speaking the forbidden, he merits a hidden light that no angel can fathom.

“Scripture states: ‘If you will seek it like silver and hunt for it like hidden treasures, then you will understand the fear of Hashem, and knowledge of God you will find‘ (Mishlei 2:4-5).

One must strive to attain spiritual goals in the way that he would seek the greatest valuables that this world has to offer. This is the intent of the statement, ‘Do not distance yourself from a quality that is without limit.’  (R’ Yochanan ben Dehavai)   Avoiding forbidden speech brings infinite merit; if we will only pursue this quality, and not tell ourselves that it is out of our reach, then we will have achieved that which no angel can fathom.” ~ The Chofetz Chaim