This pasuk implies that the source of all the punishment is serving Hashem with a lack of joy. The Arizal states that precisely because Klal Yisrael served Hashem in a lackluster manner, without vitality and joy, they would ultimately serve their enemies. Joy is an essential component of avodas Hashem, serving Hashem. Indeed, if we would not have failed to serve Hashem with joy, we would not have been exiled.
The Yalkut Me’am Loez explains this idea with a simple, but profound analogy. The king of a certain country had a son that was not controllable, His unrestrained acts of self-indulgence often were a source of embarrassment to his father. Whenever his father was about to punish him, the son would put on a sweet angelic smile. When the father observed the happiness and sweet innocence in his son’s eyes, it became difficult for him to execute his planned punishment.
This, explains the Yalkut, is a powerful deterrent from punishment. When Hashem sees the apparent joy and happiness emanating from an individual’s avodas Hashem, He defers punishment. Joy in performing mitzvos is essential. Even if a person is intellectually aware of the significance of Torah and appreciates the value of Torah life, he must experience this through joy. Unless one recognizes the inherent joy with which Judaism imbues us, he may turn elsewhere to pursue happiness.
