Layers of Emptiness leading to Nibanna
This is a short talk of Ajahn Maha Boowa who practiced under the tutelage of Venerable Acariya Mun. The first half gives the background of how Ajahn Maha Boowa found Acariya Mun. The details of types of emptiness leading to nibanna are given in the latter part. One is left hanging as to investigate and directly experience for one self.
This is the nitty gritty of the Thai Forest practice at the level of mind.
Here are links to the video and also a transcript.