Lha-Bab Duchen marks the anniversary when Lord Buddha Shakyamuni descended to The Heaven of Thirty-Three, where Maya, the Buddha's mother, was reborn after her death. In order to repay his mother's kindness by liberating her from Samsara, the Buddha spent the three summer months of that year teaching her and the gods in that realm.

On Lha Bab Duchen, the effects of positive and negative actions are multiplied ten million times. 

It is taught throughout the Buddha's teachings and their commentaries that the effects of virtue and wrong doing are billions of times more powerful on the four great occasions connected with the Buddha's life.