According to Donald Parry, often found in scriptural poetry are two or more lines which deliberate and explain what was first said in line one. This is called exergasia (Greek, "working out"), because these subsequent lines "work out" and explain the words introduced in the first line. A good example is found in Helaman 1:31:
And now, behold, the Lamanites could not retreat either way,
neither on the north,
nor on the south,
nor on the east,
nor on the west,
for they were surrounded on every hand by the Nephites.
[Donald W. Parry, The Book of Mormon Text Reformatted according to Parallelistic Patterns, F.A.R.M.S., p. xxxi]