Another theory says that 108 means to get rid of Shikuhakku (hardship): in Japanese, four, nine, eight is pronounced 'shi', 'ku', 'ha(tchi)', respectively, and 4X9+8X9 could be pronounced Shikuhakku and 4X9+8X9 is equal to 108.
四苦八苦を取り払うということで、4×9+8×9108をかけたとも言われている。