whatever notion may arise, never to let it live or grow, but to turn it that instant, firm and stern, back to it's source and merge it there, this is robust intense detachment.


okay this comes easy to me these days, i get it. sri ramana's really on to something here, he's nailing something really revolutionary, it's extreme and demanding and also somewhat impossible. 
he's suggesting that when you are confronted with some kind of notion, an opinion, judgement or external value, a criticism, something that just don't feel right or something that comes from a bad place, a corrupted thought process you can let it go. it belongs to the person who sends it, comes from them, it's their creation and therefore should have no attachment to you unless you chose to keep hold of it. 
the more one practices detachment, even of ones own thoughts and negative energies the less hold they have over you.
and the hard bit is understandably applying it to your own thoughts, the ones that fill you with insecurity and fear, these need to be understood, acknowledged as nothing more than thoughts and released as love.