About This Teaching
While attending on Ajahn Mun, Ajahn Jia's samādhi deepened and nimittas began to appear: inner images of lights, colours or shapes as vivid as things seen with the eyes. Unsure whether to engage them, he asked Ajahn Mun, who said that if they were mere distraction they should be ignored, but to understand them one must question the vision and wait for it to show its meaning. In themselves nimittas are not real or trustworthy, though skilled meditators can use them carefully as tools for wisdom.
His visions mostly concerned the body. Once he fell headfirst into a bottomless abyss, bracing for death, until the vision vanished. Another time his trunk swelled as wide as a giant water tank, as if about to burst.
Ajahn Mun explained that although these seemed to lie out in front, they were created inside the mind. He told him to stop chasing them, reverse the outward flow of awareness, and investigate the body images at their source within. Trusting nimittas can destabilise the mind; the only safe way is to bring them inside and investigate.