The Dhammapada - 11 & 12

Thinking to be essential, what is not, 

seeing no essence in what is essential, 

feeding on wrong thoughts, 

do not discover the essence.   

One can of course never expect to understand, or get close to, the "essence", the heart of the problem, if one keeps looking in the wrong direction. This is true in every field of our endeavor. Therefore this rule necessarily applies also to spiritual efforts. This verse says that if we mistake the essential things for nonsense and think that there is some essence in things that are actually empty of it, we cannot ever get even close to the reality. All kinds of superstition fall into this category, various activities that (although they look nice and can be even pleasant) do not bring us closer to the goal, which is the purification of mind. As the verse notes, this is the "pasture for wrong thoughts". As the cows on the pasture, the thoughts, wandering in this direction, will grow stronger and will multiply. The only problem is -- it will not help us on our way at all.

Having known the essence as the essence,

non-essential as non-essential, they,

feeding on right thoughts, discover the essence.

In contrast to DhP 11, if we really know, what is important and what is empty, if we know, where the essence lies, it is possible for us to discover it. We can take as an example the case if we want to clean the dirty floor. It will not help us to start scrubbing the table. Sure, a clean table is a nice thing, but we wanted the floor to be clean, not the table. In the same way, if we want to purify our mind, we must carefully decide and understand, how to do it, what is the correct procedure. If we know, what is essential in order to reach our goal, then we have a chance of accomplishing it. This is a "pasture for right thoughts". The right thoughts will grow and multiply -- this time only for our benefit.