I don’t know. This is the answer.

In other words, while “one” requires the act of combining, reason, which uses words to think, basically has the opposite essence of dividing. (仏教新論　Masahiro Mori）

Understanding” in the head is an act of using words. It cannot be expressed in more than a combination of the syllables of “abcde. The true world exists before understanding (dividing). If that is the case, then the answer is that we do not know.

The moment you understand, you have already slipped away. Mr. Mori describes this unspoken understanding as “settling down to the bottom of the heart with a thud,” but I think that is unnecessary.