How many of you have played piano, violin, guitar, or any other string instrument? For those of you who have not played a string instrument, it's exactly as Rosemary says in the regular retreat. There are these knobs that you adjust to tune the instrument. If you turn it too tight the instruments goes, "ding, ding", if you turn it too loose the instrument goes, "dock dock". It's exactly true. Balancing our efforts is similar to tuning a string instrument - when it's too tight it goes one way, when it's too loose it goes the other way.
That's basically what this person is talking about, and in order to develop a balanced effort you have to practice, you have to learn. When I was taught to play the guitar, like most guitars, it had six strings. The strings had to correlate to each other, and I had to really, really listen, I had to catch those little sounds. After a while, I could actually tune one string by itself without correlating it to another because my hearing had become so fine that I knew exactly what that string should sound like. How did I know, how did I develop that? Because I practiced over and over and over. Over and over and over. Over and over and over.
Too hard or too gentle - if you find you're getting too loose, you may find you are not bringing up enough energy - ok, put in some hardness. If you find you are getting too tight, ok, put in some gentleness. In that way, we can come to find the right balance.