Today I went to a session by Ajhan Brahm who suggested 'stilling' as the best translation, and that concentration was a very poor translation.
Also this gives some hints as to what it is about:
"As for the individual who has attained insight into phenomena through heightened discernment, but not internal tranquillity of awareness, he should approach an individual who has attained internal tranquillity of awareness... and ask him,
'How should the mind be steadied? How should it be made to settle down? How should it be unified? How should it be concentrated?' The other will answer in line with what he has seen & experienced: 'The mind should be steadied in this way. The mind should be made to settle down in this way. The mind should be unified in this way. The mind should be concentrated in this way.' Then eventually he [the first] will become one who has attained both internal tranquillity of awareness & insight into phenomena through heightened discernment.
http://www.accesstoinsight.org/tipitaka ... .than.htmlAlso..
"[9] He trains himself, 'I will breathe in
sensitive to the mind.' He trains himself, 'I will breathe out sensitive to the mind.' [10] He trains himself, 'I will breathe in
satisfying the mind.' He trains himself, 'I will breathe out satisfying the mind.' [11] He trains himself, 'I will breathe in
steadying the mind.' He trains himself, 'I will breathe out steadying the mind.' [12] He trains himself, 'I will breathe in
releasing the mind.' He trains himself, 'I will breathe out releasing the mind.'[5]
with metta
Matheesha