Tenrikyo-Ofudesaki - Sure Guides to Understanding the Intention of the Poems
Many very bright and intelligent people do not know the meaning of the hastening to "ponder deeply". It is just something that has not come up in their life experience.
We know that in the poems The Tip Of The Writing Brush the word "water" is a metaphor for the human mind. Everyone in the world knows what water is and everyone in the world can tell the difference between "clear water" and "muddy water". That however is not the case when it comes to our own mind. To be aware of the difference between "clear" and "muddy" as those metaphors apply to our own mind it is necessary to first become aware of what our mind is. To do that we will have to shift our attention away from the common details and flow of our thinking and instead turn our attention inward and become aware of our mental processes. For some of us that is a mental voice, while for others it is mental pictures or perhaps a combination of both.