I was reminded of this phrase from Buddhist teachings when hearing of some of the meditation experiences in the group. Shamata properly practiced can lead to an experience of vibrant emptiness in which self is temporarily suspended, returns and evaporates again. This is consciousness moving in and out of a state that is unsupported and unconfined by self and the things we identify with. It’s spacious, alive, non-reactive.
Dull shamata often comes to those who meditate on their own and fall into a trance-like state that is non-reactive and empty but not alive and spacious. This is in fact a fairly steady state, somewhat easily maintained because it is a production of self. Beware of dull shamata, meditators.