Why is the moon and not the sun symbol for wisdom enlightentment in zen?

September 10, 2016, 6:57 am

"How vast and wide the unobstructed sky of samadhi! How bright and clear the perfect moonlight of the Fourfold Wisdom!"

In a dark night when the moon rises, this light of the moon make us be able to see in the dark, shining this light onto our mind and purifying it.