The most famous Dvar Torah about the verb “to know” is that the Rambam opens his Mishneh Torah with the statement that the foundation of foundations and pillar of all wisdom is to KNOW that there is a First Cause, that guides the world. Not to believe, but to know. The distance between believing and knowing is not as great as one would think.
How is that? Isn’t believing an irrational thing, a religious concept?
No it’s not. Believing is part of the spectrum of epistemology, the understanding of how we come to know things.
We all know things that we have not used the famous five senses to apprehend. Firsthand, even if we haven’t seen or heard something, we draw conclusions all the time.
The power of drawing a conclusion all depends on the evidence available.
I would argue that the real difference between belief and knowledge is related to the amount and quality of the evidence. To KNOW something means to have the conclusion based on convincing evidence.
Mulling that over should be enough for today.
Sometimes the knowledge is derivative. If I know that a source is trustworthy, then I can be said to “know” that what they say about the topic they are trustworthy about is true.