לזכות ולברכה לשמואל אלכסנדר בן נעכא גיטל
Rashi says [Bamidbar 29/18] that the 98 lambs we bring on succos are in order to cancel out the 98 curses in sefer dvarim. The Sochochover Rebbe explained that the reason for all of the curses is because we didn't serve Hashem with simcha, and succos is "zman simchaseinu" so we fix it.
נאות דשא עמוד 247