These sayings are hard
I have little handle on these ones. This leads me to suspect they are of more Gnostic origins -- they assume an oral teaching that has not survived and so we lack the context and tools. No, I lack the context and tools, to decode, interpret, to understand. It may be the Thomas community had "secret teachings" allowed only to initiates. And, as Logion 1 warns us, only those who can interpret these saying may live.
Hermetic and alchemical symbolisms, one of the heirs to gnosticism, associates, one with purity, and plurality with contamination. Perhaps this is a start. But we have Darwin amongst our modern day prophets. The God who made all made a plurality. In terms of human enterprise a corn field may be superior to a meadow, but a meadow, buzzing with life and diversity seems to be God's creativity at work. In human enterprise the value of anything is single minded, to paraphrase Oscar Wilde, it knows the value ($$$) but not its worth.
Another possibility. Modern science has inherited Aristotle's approach to knowing. For Aristotle we understand something when we know which category it stands under. In other words, when we can pigeon-hole it he know it. Aristotle taught Western philosophy to categorize everything according to genus and species. What group does it belong to? How does it differ from other members of its grouping?
There are other ways of knowing that Western ways have marginalized. Krishnamurti is a modern sort of speaker to some of that. Another approach is some teachings of zen. From these stances, knowledge doesn't come through conceptualization, but by setting aside the concepts and observing from detachment. I wonder if this is a part of what Thomas is saying?