Inclusio
In literature there are many ways to enclose text within text. A simple way is to use parentheses ( these are parentheses) to set text apart. The ancient Hebrews authors loved inclusio. Inclusio is type of bracketing, or enveloping by placing similar material (or words) at the beginning and the end of a section.
Ancient Babylonian tablets which predate Abraham, used verbal bracketing as a way to indicate when an account was finished. This was necessary because clay tablets were small; a story may run across two or more tablets. When the original tablets were transcribed on papyrus (while in the library in Egypt), they still signify the contents in the literary envelope.
When speaking of rhyming we use letters to indicate the rhyme pattern; such as AABBA for lymerics.
We use similar notation for an inclusio as A-B-A where A is the pattern which is at the beginning and end of the section; B is the content enveloped by the inclusio. Other Patterns may be indicated within the inclusio such as: A-BCD-BCD-A or A-BC-D-CB-A.