It is useless to stack up a pile of treasures in your storehouse if you are in poor health. Therefore, the value of a healthy body is more precious than treasures in the storehouse. At the same time, however, a healthy body means nothing if your mind is not pure. This is why we can say that our most precious treasure is our mind itself. Upon reading this letter, please try to accumulate the treasure of your mind.

Sushun Tennō Gosho, The ‘Emperor Sushun’ Letter, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 123