The Gemara in Maseches Sukkah describes the unbounded joy of Simchas Beis Hasho'eivoh celebrated in the Beis Hamikdosh (Holy Temple) from the Second night of Sukkos until the end of Chol Hamoed (the Intermediate Days). "He who has not witnessed the joy of Beis Hasho'eivoh has never seen joy in his lifetime." The Gemara adds that, in their greatest ecstasy, the "Chassidim and men of good Deeds" never overlooked the pressing need of repentance. Dancing together fervently they would sing out:
אֵלּוּ וָאֵלּוּ אוֹמְרִים: אַשְׁרֵי מִי שֶׁלֹּא חָטָא, וּמִי שֶׁחָטָא יָשׁוּב וְיִמְחוֹל לוֹ.
"Fortunate is he who has not sinned; and let one who has sinned repent, and he will be forgiven."
This moving melody, composed by early Chabad Chassidim, accurately brings forth the message of the melody to contemplate repentance even in moments of highest rapture.