[irrational]

This is called a Chiastic structure (from the greek letter chi which looks like an X - i.e., the shape the chiastic structure makes if you indent each succeeding level).

https://en.wikipedia.org/wiki/Chiastic_structure

"These often symmetrical patterns are commonly found in ancient literature such as the epic poetry of the Iliad and the Odyssey."

[hnaa]

https://theopolisinstitute.com/the-chiastic-structure-of-lor...

[hnaa]

I've been thinking about this and Shakespeare's King Lear may be an example of this as well.

[hnaa]

Also in Milton's Paradise Lost, I believe.