Luang Pu Doo

Luang Pu Doo once commented that there are 3 reasons as to why a monk's body would not decompose. 

The first is that the master could have been an expert in spells and incantations, and he could have blessed his rice before eating everyday, which is converted into an indestructible body. 

The second is someone who soaks in herbal baths or eats certain kinds of herbs (read Luang Phor Jumnean's story of how his father made his skin impenetrable to weapons if you are interested). 

Then there is the third kind, someone who has reached high stages of enlightenment, such as arahants who adithans (make a strong determination) that his body does not decay after his death.

The undecomposed body of the great Arahant Phra Kru Athon Phatthanakun of Wat Na Udom, Tan Sum District, Ubon Ratchathani Province. Luang Pu Ya Than Suan looks like he has just fallen into a deep slumber, since 2549 until today.