The primal mind is radiant and clear by nature, but is darkened because of corruptions.

pabhassaramidam bhikkhave cittam
tanca kho agantukehi upakkilesehi upakkilittham:

'Monks, this mind is originally radiant and clear, but because passing corruptions and defilements come and obscure it, it doesn't show its radiance.' This has been compared to a tree in the poem that runs,

A tall tree with 6,000 branches:
Big chameleons swarm it each day by the hundreds,
Small chameleons, each day by the thousands.
If the owner doesn't watch out,
They'll bring along more and more of their friends every day.

This can be explained as follows: The tall tree with 6,000 branches — if we cut off the three zeroes, this leaves us with six, which stands for the six sense doors, the entry way for the chameleons, i.e., things that are counterfeit, not things that are genuine. Defilements aren't genuine. They are simply things that come drifting in through the sense doors by the hundreds and thousands. Not only that, defilements that haven't yet arisen will arise more and more every day as long as we don't find a means for rectifying the nature of the mind.
The mind is something more radiant than anything else can be, but because counterfeits — passing defilements — come and obscure it, it loses its radiance, like the sun when obscured by clouds. Don't go thinking that the sun goes after the clouds. Instead, the clouds come drifting along and obscure the sun.
So meditators, when they know in this manner, should do away with these counterfeits by analyzing them shrewdly, as explained in the strategies of clear insight. When they develop the mind to the stage of the primal mind, this will mean that all counterfeits are destroyed, or rather, counterfeit things won't be able to reach into the primal mind, because the bridge making the connection will have been destroyed. Even though the mind may then still have to come into contact with the preoccupations of the world, its contact will be like that of a bead of water rolling over a lotus leaf.


Ajaan Mun