"One of the most interesting and intricate biblical literary
structures is called a chiasm. It takes its name from the Greek
letter chi, written X, because it has a structure that crosses over
somewhat like an 'X.' Or a form suggested by its conforming to the
">" shape of the left half of the Greek letter chi, which
is drawn like the English X. The "outer" elements, designated
AA', are the "frame". In a chiasm, the various elements
of a writing are related to each other in parallels so that the first
and the last are parallel, the second and the second from the last
are also parallel, and so on. There can be two or more elements.
"The most simple example is the saying of Jesus: "The
first shall be last and the last shall be first." The chiasm
is first - last - last first, forming the pattern, AB B'A'. But the
structure can be developed even more to have a central element that
stands by itself, around which the other parts circle, and can serve
as a center and theme for the whole writing.
"It might be helpful to think of chiasm as saying things forwards
and backwards." --Ron Corson, Chiastic
Structure and Isaiah 14
