'Knowings' in this sense has not been influenced by external stimulus. One can know things about our environment using the six
senses as a substrate between the seeming reality out there and the
seeming mind in here.
There five external senses rather than six.
However, one can also have a knowing that occurs apparently
separate from this process.
There is no knowing apart from the six senses.
Intuition in the question here refers to an instinctual awareness that something is so but interestingly the intuition hasn't arisen
through the conventional methods of learning; there has been no
previous auto-suggestion.
A living organism has a nervous system that functions based on feelings (of pleasure and pain) and underlying tendencies (such as survival instinct & fear). Often "intuition" is based in fear of the unknown; which gives rise to a certain sense of "caution". Since life is full of unpredictable & impermanent events, often the sense of cautious intuition seems valid (even though its validity is actually only due to the probability that most worldly scenarios won't be successful).
The knowing itself is the knowing of rebirth. It has been something I've steered well clear of but, suddenly, there was the clear knowing
that rebirth is so.
There is no evidence for such thing as "rebirth". "Rebirth" ideas arises from the fear I mentioned above; the fear of the "self" or "ego" not wanting to die.
Note: In the Buddhist suttas, the word "rebirth" refers to the future results that occur due to past actions. For example, killing leading to rebirth in "hell" (trauma; prison; regret; etc). "Rebirth" is not the intuition you existed before due to fear of "ego-death".
As I already posted, people practise meditation and then the ego does not want to die. Therefore, the mind, due to fear, starts creating ideas of past & future existence.
Thus the conflict occurs - if I have relied on my six senses all my life to know things, how could I know rebirth to be so?
Ideas of rebirth are mental thoughts and objects. They are known by the 6th sense; similar to how dreams in sleep are known by the 6th sense. Dreams at night show how creative and imaginative the mind can be.
What on earth is 'Mind'??? Where is Mind'??? (Rhetorical questions but if you're feeling cognitively malleable then feel free to answer
these also!)
The above question falls outside of the scope of Buddhism. Buddhism says there is mind and, to be free from suffering, mind must not be clung to as "I", "me" or "mine". Buddhism is only about ending suffering.