"a literary technique in which a narrative segment is interrupted by the embedding of a second narrative segment (a Zwischenepisode) within the first, after which the threads of the first are picked up again, producing an ABA' pattern of composition. . . .
"Intercalations occur at least six times in Mark. . . ."
David E. Aune, The Westminster dictionary of New Testament and early Christian literature and rhetoric (Louisville, KY: Westminster John Knox Press, 2003), 230 (230-232), where there is, of course, much more, and a bibliography to boot. REF BS2312 .A86 2003.